abort: case-folding collision

[Shane Holloway]

[shane at dynamic-48] Dev/TG% hg clone tgav tmp/tgav
abort: case-folding collision between sandbox/opengl/glext/ 
fetchOpenGLExtensions.py and sandbox/openGL/glext/ 
fetchOpenGLExtensions.py

I do not have a good understanding of what is going on here, nor how  
to fix it.  It is a local repo on my machine only.  I'm the only  
writer, although I do use it from multiple terminals at the same time...

We've been using Mercurial here for a few months, and I am simply  
hooked.  Thanks for everything you all have put into this!  I am just  
getting around to trying the hgForest extension and ran into this  
problem with one of my local repos.

Thanks!
-Shane