SyLens 3.11 for Nuke-7 64b (all platforms)

This release dispenses with the Nuke 6 builds (you can still create them manually if your pipeline requires it since the code does not use any 7-specific APIs).

Fixes the bug where the "trim to bbox" knob in SyLens would reset itself to random values.

Adds the preliminary Nuke 8 Windows and Linux builds, Mac build coming soon.