added help view in the android app. The help itself is not very useful right now

src/ui/android/res/menu/main.xml

@@ -1,4 +1,6 @@
 <menu xmlns:android="http://schemas.android.com/apk/res/android" >
 	<item android:id="@+id/input_mode"
           android:title="@string/keyboard_input"/>
+	<item android:id="@+id/help"
+          android:title="@string/help"/>
 </menu>

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

@@ -7,6 +7,7 @@
 	<string name="open_image">Opening</string>
 	<string name="mic_input">Speech Input</string>
 	<string name="keyboard_input">Keyboard Input</string>
+	<string name="help">Help</string>
 	<string name="global_preferences_key">org.grammaticalframework.ui.android.GLOBAL_PREFERENCES</string>
 
     <!-- Labels on soft keys -->