* clutter/clutter-score.h: Rearrange declarations.
* clutter/clutter-score.c: More documentation in the long
description of the ClutterScore section.
* clutter/clutter-debug.h:
* clutter/clutter-main.c: Add the CLUTTER_DEBUG_SHADER flag,
for debugging the shader calls.
* clutter/clutter-feature.h: Fix the documentation of the
feature flags.
* clutter/Makefile.am: Remove trailing whitespace.
* clutter/clutter-score.[ch]: Reimplement ClutterScore using
a N-ary tree to store the timelines. Remove clutter_score_add():
the same functionality can be achieved by passing a NULL
parent to clutter_score_append().
* tests/test-score.c: Update ClutterScore test unit, and add
debug printouts.