* clutter/clutter-behaviour-depth.c:
Modify to work like all other behvaiours in not forcing
increasing order in behaviour 'limits'. (#436)
Rename limit min/max props to start/end.
* tests/test-depth.c:
Simplify test-case to work with above change and
without multiple ramps
* clutter/clutter-behaviour-rotate.c:
Handle CW rotation when end > start and similar for CCW just
like ellipse behaviour.