Reasonably safe changes.

Using accessor for vertexbuffer in LLFace
Extra occlusion query lookup in llgl (unused)
Const changes.

indra/llrender/llglslshader.h

@@ -109,7 +109,7 @@ public:
 	void vertexAttrib4fv(U32 index, GLfloat* v);
 	
 	GLint getUniformLocation(const std::string& uniform);
-	
+	GLint getAttribLocation(U32 attrib);
 	GLint mapUniformTextureChannel(GLint location, GLenum type);