Tests improvements

CPLayoutConstraintPerfTest manual test now shows 2 fractal-like layout,
the constraint based being generated from autosize masks.

ojtest CPLayoutConstraintTests now tests the same fractals than the
manual test. Note that we purge the runloop after each window resize
because view frames are updated on layout in auto layout mode.
Make _CPViewUpdateEngineFrame a file scope function
Manual Test
FIXED: constraint priority between 0 and 1000
FIXED: CPView -setContentCompressionResistancePriority:

setContentCompressionResistancePriority:forOrientation:
was not working.
CPLayoutConstraint: use hash instead of uuidgen
Renamed CPLayoutConstraintTest -> ConstraintEditor

Now edits constant, priority, intrinsicSize of constraints created with
IB.
TODO: UI for adding constraints.
Merge branch 'Autolayout' of github.com:cacaodev/cappuccino into Autolayout