loading and unloading of languages in the C runtime and in the Python bindings

src/runtime/java/org/grammaticalframework/pgf/Concr.java

@@ -27,6 +27,12 @@ public class Concr {
 
 	public native boolean hasLinearization(String id);
 
+	public native void load(String path) throws FileNotFoundException;
+
+	public native void load(InputStream stream);
+
+	public native void unload();
+
 	//////////////////////////////////////////////////////////////////
 	// private stuff