Key bugfixes

Fixed bug where setfocus would trigger another click when tab or
shift-tab used.

Prevented replot of all patches on every display update.

Sped up plotting of updated cuts.
Merge remote-tracking branch 'origin/master' into ari
Fixed shift-tab bug

Fixed bug in shift-tab functionality.
Overview no longer redraws all patches

Fixed so updateOverviewDisplay no longer has to redraw every patch.
Greatly improves saving and deleting speed.

When deleting objects a history is kept. roiInfo.roi(deletedROI) will
remain, but the index in grouping will be set to NaN and the index will
be removed from roiList.
Fixed sliders

Implemented sliders to change contrast
Ignore out-of-bounds clicks when zoomed

Modified cbMouseclick to ignore out-of-bounds clicks even when zoomed
in.
Don't delete impoint

Made it so impoint remains so user can tell where last clicked.