Add new Android voice translator sample app

This adds a simple voice translator Android app that uses
the JNI bindings to the PGF C runtime.

Caveats:

- Since the C runtime doesn't compile for Android right now,
  I've bundled an old copy, along with its Java bindings.
  That should be removed once the C runtime compiels for Android
  again.

- Adding an automated build would be nice.

- Replacing the grammar requires editing a Java file, that should 
  really be more dynamic.

src/ui/android/res/drawable/first_person_utterance_bg.xml

@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="utf-8"?>
+<shape xmlns:android="http://schemas.android.com/apk/res/android"
+    android:shape="rectangle">
+    <corners android:radius="4dp" />
+    <solid android:color="#75CD75" />
+</shape>

src/ui/android/res/drawable/second_person_utterance_bg.xml

@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="utf-8"?>
+<shape xmlns:android="http://schemas.android.com/apk/res/android"
+    android:shape="rectangle">
+    <corners android:radius="4dp" />
+    <solid android:color="#7575CD" />
+</shape>

src/ui/android/res/layout/activity_main.xml

@@ -0,0 +1,85 @@
+<?xml version="1.0" encoding="utf-8"?>
+<RelativeLayout
+        xmlns:android="http://schemas.android.com/apk/res/android"
+        android:layout_height="match_parent"
+        android:layout_width="match_parent"
+        >
+
+    <RelativeLayout
+            android:id="@+id/top_bg"
+            android:layout_height="wrap_content"
+            android:layout_width="match_parent"
+            android:layout_alignParentTop="true"
+            android:layout_alignParentLeft="true"
+            android:layout_alignParentRight="true"
+            android:padding="8dp"
+            android:background="#C0C0C0"
+            >
+
+        <ImageView
+                android:id="@+id/start_stop"
+                android:layout_height="wrap_content"
+                android:layout_width="wrap_content"
+                android:layout_alignTop="@+id/source_language"
+                android:layout_alignBottom="@+id/target_language"
+                android:layout_alignParentRight="true"
+                android:padding="8dp"
+                android:src="@drawable/ic_mic"
+                android:background="?android:attr/selectableItemBackground"
+                android:contentDescription="@string/microphone"
+                />
+
+        <ImageView
+                android:id="@+id/switch_languages"
+                android:layout_height="wrap_content"
+                android:layout_width="wrap_content"
+                android:layout_alignTop="@+id/source_language"
+                android:layout_alignBottom="@+id/target_language"
+                android:layout_toLeftOf="@id/start_stop"
+                android:padding="8dp"
+                android:src="@drawable/ic_action_switch"
+                android:background="?android:attr/selectableItemBackground"
+                android:contentDescription="@string/switch_languages"
+                />
+
+        <org.grammaticalframework.ui.android.LanguageSelector
+                android:id="@+id/source_language"
+                android:layout_height="wrap_content"
+                android:layout_width="match_parent"
+                android:layout_alignParentLeft="true"
+                android:layout_alignParentTop="true"
+                android:layout_toLeftOf="@id/switch_languages"
+                android:padding="0dp"
+                />
+
+        <org.grammaticalframework.ui.android.LanguageSelector
+                android:id="@+id/target_language"
+                android:layout_height="wrap_content"
+                android:layout_width="match_parent"
+                android:layout_below="@id/source_language"
+                android:layout_toLeftOf="@id/switch_languages"
+                android:padding="0dp"
+                />
+
+    </RelativeLayout>
+
+    <org.grammaticalframework.ui.android.ConversationView
+            android:id="@+id/conversation"
+            android:layout_height="match_parent"
+            android:layout_width="match_parent"
+            android:layout_alignParentLeft="true"
+            android:layout_alignParentBottom="true"
+            android:layout_alignParentRight="true"
+            android:layout_below="@id/top_bg"
+            >
+        <LinearLayout
+                android:id="@+id/conversation_content"
+                android:layout_height="wrap_content"
+                android:layout_width="match_parent"
+                android:orientation="vertical"
+                android:padding="16dp"
+                >
+        </LinearLayout>
+    </org.grammaticalframework.ui.android.ConversationView>
+
+</RelativeLayout>

src/ui/android/res/layout/first_person_utterance.xml

@@ -0,0 +1,11 @@
+<TextView
+        xmlns:android="http://schemas.android.com/apk/res/android"
+        android:layout_height="wrap_content"
+        android:layout_width="wrap_content"
+        android:layout_marginBottom="16dp"
+        android:layout_marginRight="32dp"
+        android:layout_gravity="left"
+        android:padding="8dp"
+        android:textSize="20sp"
+        android:background="@drawable/first_person_utterance_bg"
+        />

src/ui/android/res/layout/languages_item.xml

@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="utf-8"?>
+<TextView
+        xmlns:android="http://schemas.android.com/apk/res/android"
+        android:layout_height="wrap_content"
+        android:layout_width="match_parent"
+        android:padding="8dp"
+        android:textSize="20sp"
+        />

src/ui/android/res/layout/second_person_utterance.xml

@@ -0,0 +1,12 @@
+<?xml version="1.0" encoding="utf-8"?>
+<TextView
+        xmlns:android="http://schemas.android.com/apk/res/android"
+        android:layout_height="wrap_content"
+        android:layout_width="wrap_content"
+        android:layout_marginBottom="16dp"
+        android:layout_marginLeft="32dp"
+        android:layout_gravity="right"
+        android:padding="8dp"
+        android:textSize="20sp"
+        android:background="@drawable/second_person_utterance_bg"
+        />

src/ui/android/res/values-sw600dp/dimens.xml

@@ -0,0 +1,8 @@
+<resources>
+
+    <!--
+         Customize dimensions originally defined in res/values/dimens.xml (such as
+         screen margins) for sw600dp devices (e.g. 7" tablets) here.
+    -->
+
+</resources>

src/ui/android/res/values-sw720dp-land/dimens.xml

@@ -0,0 +1,9 @@
+<resources>
+
+    <!--
+         Customize dimensions originally defined in res/values/dimens.xml (such as
+         screen margins) for sw720dp devices (e.g. 10" tablets) in landscape here.
+    -->
+    <dimen name="activity_horizontal_margin">128dp</dimen>
+
+</resources>

src/ui/android/res/values-v11/styles.xml

@@ -0,0 +1,11 @@
+<resources>
+
+    <!--
+        Base application theme for API 11+. This theme completely replaces
+        AppBaseTheme from res/values/styles.xml on API 11+ devices.
+    -->
+    <style name="AppBaseTheme" parent="android:Theme.Holo.Light">
+        <!-- API 11 theme customizations can go here. -->
+    </style>
+
+</resources>

src/ui/android/res/values-v14/styles.xml

@@ -0,0 +1,12 @@
+<resources>
+
+    <!--
+        Base application theme for API 14+. This theme completely replaces
+        AppBaseTheme from BOTH res/values/styles.xml and
+        res/values-v11/styles.xml on API 14+ devices.
+    -->
+    <style name="AppBaseTheme" parent="android:Theme.Holo.Light.DarkActionBar">
+        <!-- API 14 theme customizations can go here. -->
+    </style>
+
+</resources>

src/ui/android/res/values/dimens.xml

@@ -0,0 +1,7 @@
+<resources>
+
+    <!-- Default screen margins, per the Android Design guidelines. -->
+    <dimen name="activity_horizontal_margin">16dp</dimen>
+    <dimen name="activity_vertical_margin">16dp</dimen>
+
+</resources>

src/ui/android/res/values/strings.xml

@@ -1,8 +1,9 @@
 <?xml version="1.0" encoding="utf-8"?>
 <resources>
 
-    <string name="app_name">GFTranslator</string>
-    <string name="action_settings">Settings</string>
-    <string name="hello_world">Hello world!</string>
+    <string name="app_name">GF Translator</string>
+
+    <string name="microphone">Microphone</string>
+    <string name="switch_languages">Switch languages</string>
 
 </resources>

src/ui/android/res/values/styles.xml

@@ -0,0 +1,20 @@
+<resources>
+
+    <!--
+        Base application theme, dependent on API level. This theme is replaced
+        by AppBaseTheme from res/values-vXX/styles.xml on newer devices.
+    -->
+    <style name="AppBaseTheme" parent="android:Theme.Light">
+        <!--
+            Theme customizations available in newer API levels can go in
+            res/values-vXX/styles.xml, while customizations related to
+            backward-compatibility can go here.
+        -->
+    </style>
+
+    <!-- Application theme. -->
+    <style name="AppTheme" parent="AppBaseTheme">
+        <!-- All customizations that are NOT specific to a particular API-level can go here. -->
+    </style>
+
+</resources>