Fix color and depth buffer cache for windows that change size.  Fix documentation referring to "singleton" buffer manager instead of per-context.
Fix color and depth buffer cache for windows that change size.  Fix
documentation referring to "singleton" buffer manager instead of per-context.



git-svn-id: d4fdfcd4de20a449196f78acc655f735742cd30d@2144 14d46d22-621c-0410-bb3d-6f67920f7d95

regular/pyglet-avbin-optimizations,regular/pyglet-avbin-optimizations,regular/pyglet-avbin-optimizations,regular/pyglet-avbin-optimizations