emulator opengl: add GLESv2 support to driver + renderer

Added GLESv2 library to system.
Made fixes to the host libOpenGLRender to
compile and support GLESv2 (defined WITH_GLES2).
Other fixes required to make GLESv2 to work.

Change-Id: I9eb198e6092e7fa3550342c50929dd1714282cb3

tools/emulator/opengl/host/libs/libOpenglRender/GL2Dispatch.cpp

@@ -41,7 +41,8 @@ bool init_gl2_dispatch()
     //
     // init the GLES dispatch table
     //
-    return s_gl2.initDispatchByName( gl2_dispatch_get_proc_func, NULL );
+    s_gl2.initDispatchByName( gl2_dispatch_get_proc_func, NULL );
+    return true;
 }
 
 //