Most of these fixes are simple symbol shadowing issues, like index and the
braindead y0 and y1 extern symbols exported by math.h on GNU libc systems.
There is a masking issue in ClutterTexture which should be checked; I ran
the tests and everything looked fine.
The rest are just unused variables.
* clutter/clutter-actor.h:
* clutter/clutter-stage.h: Add 32 padding slots; when we
reach 1.0 it'll be a long road until the following ABI
break.
* tests/test-behave.c: Don't forget to include headers.
