The master clock now works fine whether or not there are any stages,
so in the timeline conformance tests don't need to set up their
own times.
Set CLUTTER_VBLANK=none for the conformance tests, which in addition
to removing an test-environment dependency, will result in the ticking
for timeline tests being throttled to the default frame rate.
http://bugzilla.openedhand.com/show_bug.cgi?id=1637
Signed-off-by: Emmanuele Bassi <ebassi@linux.intel.com>