Fixed save measure, save point in the control point editor. Clear out editor...

Fixed save measure, save point in the control point editor. Clear out editor if a deleted point is loaded.  Added shortcuts to control point editor, update display of points on footprintview when point deleted.  Fixes #4982, #4984, #5073.

git-svn-id: http://subversion.wr.usgs.gov/repos/prog/isis3/branches/ipce@8003 41f8697f-d340-4b68-9986-7bafba869bb8