MER: Add systrace support.

Not upstreamable, just like the parent feature (systrace support) isn't.
QQuickPinchArea: Don't jump around when a finger is lifted.

Done-with: Martin Jones <martin.jones@jollamobile.com>
Build V4 with JIT, thanks to thumb.
[qtdeclarative] Touch event compression in QQuickWindow.

Change-Id: Ia0169bc4a3f0da67709b91ca65c326934b55d372