Optimised rendergl to only output graphic names when picking, start/end spectrum rendering once for a series of surfaces, and output multiple discontinuous surfaces with one glBegin/glEnd when possible.  https://tracker.physiomeproject.org/show_bug.cgi?id=2064
Optimised rendergl to only output graphic names when picking, start/end spectrum rendering once for a series of surfaces, and output multiple discontinuous surfaces with one glBegin/glEnd when possible.  https://tracker.physiomeproject.org/show_bug.cgi?id=2064

git-svn-id: 4705079bc6b8aadf675e3696f5c015a6aa4916e3@6669 3c1deb5b-d424-0410-962d-aba41a686d42

OpenCMISS/zinc,OpenCMISS/zinc,OpenCMISS/zinc,hsorby/zinc,hsorby/zinc,hsorby/zinc,OpenCMISS/zinc,hsorby/zinc