GUI -- Augmented pan/zoom & select/drag integration by having a toggle button for whether meta needs to be pressed for panning (default) or selecting.
 - multi-select requires the shift key to be held down.
 - Also re-wired deselectAll() to the ESC key, instead of click on background.

Change-Id: I63502839368c6ca10c64ee583a58f836576c4546
3 files changed