Added safety prompts when turning edit lock off for single or multiple cells....

Added safety prompts when turning edit lock off for single or multiple cells. Edit widget now saves data when the enter key is pressed.

git-svn-id: http://subversion.wr.usgs.gov/repos/prog/isis3/trunk@2944 41f8697f-d340-4b68-9986-7bafba869bb8