Code review comment for lp:~compiz-linaro-team/compiz/gles2

OK, I /think/ the worst of the Unity regressions are now fixed, or at least with fixes proposed:
https://bugs.launchpad.net/unity/+bugs?field.tag=gles

Let's open this for review again. But be aware I may not action some of the optional cleanups (already mentioned) before this branch lands.