change in texture caching

[James W. W. <os...@jw...>]

I just committed a change to the way Quesa caches textures.   
Previously, if one texture object was used in multiple texture  
shaders, you got multiple copies of the texture in OpenGL texture  
memory.  Now you just get one.  Let me know if any problems arise.

SourceForge has a partial outage concerning anonymous CVS, so you may  
not be able to get these changes by anonymous CVS right now.