Sluggish graphics performance on MAC OSX

[fr810]

Please see this thread for a recent messagemanager fix which improves performance when there are multiple OpenGLContexts active:

Performance issue with OpenGL in multiple windows

Yes, we’ve been working on fixing this. However, it needed some deep changes in the MessageManager locking implementation so we are still testing this. Can you try the following branch and let me know if this improves performance for you? This would be super valuable information for us.