ilastik.py: When recording or playing back, disable 3D.  Also, use the same QApplication type in both cases.
LayerViewerGui: Pass parent to VolumeEditor, as required by recent volumina change.
testing: Improvements to event recording system.
(Note that the entire recording system, including these changes, will soon be extracted into a separate library.)
testing: Removed recording code, which now resides in a separate repo (a new dependency)
eventcapture dependency is now optional unless you actually try to record/playback.
Added submodules dir and added eventcapture repo to it.
Updated eventcapture submodule.
submodules: Automatically discover submodules and add them to sys.path