Load OpenGL ES 2.0 function procs

Load functions procs supported by OpenGL ES 2.0, though there is not a
compatible renderer yet. Change argument for GLimp_Init from coreContext
to fixedFunction.

code/renderergl2/tr_init.c

@@ -258,7 +258,7 @@ static void InitOpenGL( void )
 	{
 		GLint		temp;
 		
-		GLimp_Init( qtrue );
+		GLimp_Init( qfalse );
 		GLimp_InitExtraExtensions();
 
 		// OpenGL driver constants