Speedup blinking and drawing pts on the viewports. Add option to draw pts in...

Speedup blinking and drawing pts on the viewports.  Add option to draw pts in the ChipViewports, if pt has sigmas, don't erase when moving the point.  Fix blinking problem with the measure table. Fixes #341 Fixes #358 Fixes #363

git-svn-id: http://subversion.wr.usgs.gov/repos/prog/isis3/trunk@3222 41f8697f-d340-4b68-9986-7bafba869bb8