Add CC3Node selectShaderPrograms method to select shaders during app startup.

Add CC3Node selectShaderPrograms method to select the shaders for each mesh node
during app startup, instead of selecting lazily. Add standard shader vars for bone
matrices in model space. Add animationFrameCount & animationFrameRate properties
to CC3PODResourceNode. Don't color individual vertices during node picking.
Track max number of texture units and vertex attribs used to avoid enabling/
disabling more than used. Clean up compilation errors in OSX release compile.