add wavefront loader

start adding various scenes to test gpu rigid body pipeline
reserve more memory for shapes (concave triangle mesh can be huge) in GLInstancingRenderer
fix a few crashes when 0 objects

btgui/OpenGLWindow/GLInstancingRenderer.h

@@ -44,7 +44,7 @@ class GLInstancingRenderer
 
 	
 public:
-	GLInstancingRenderer(int m_maxObjectCapacity, int maxShapeCapacityInBytes = 512*1024);
+	GLInstancingRenderer(int m_maxObjectCapacity, int maxShapeCapacityInBytes = 10*1024*1024);
 	virtual ~GLInstancingRenderer();
 
 	void init();