* clutter/clutter-effect.[ch]: Update the effects API to remove
the start value for most of them.
(clutter_effect_move): Make it a simple "move from current
position to new coordinates" effect.
(clutter_effect_path): Rename from clutter_effect_move().
(clutter_effect_rotate): Sync up with the new actor rotation API.
* tests/test-effects.c: Regression test for the effects.
* tests/Makefile.am: Build glue for test-effects
* tests/test-behave.c: Emulate a full ramp by using a looping
timeline changing its direction when reaching the last frame.
