Always bind a new texture to unit 1 when necessary
Always bind a new texture to unit 1 when necessary

The special handling for texture unit 1 caught the case where unit
1 was changed for transient purposes, but didn't properly handle
the case where the actual non-transient texture was different between
two materials with no transient binding in between.

If the actual texture has changed when flushing, mark unit 1 as dirty
and needing a rebind.

http://bugzilla.clutter-project.org/show_bug.cgi?id=2261

Distrotech/cogl,spatulasnout/cogl,djdeath/cogl-android,Distrotech/cogl,djdeath/cogl,djdeath/cogl-android,gcampax/cogl,collects/cogl,gcampax/cogl,djdeath/cogl,spatulasnout/cogl,djdeath/cogl,Distrotech/cogl,gcampax/cogl,collects/cogl,gcampax/cogl,Distrotech/cogl,djdeath/cogl-android