close context menus when a command executes
use PopUpManager to close menus
Merge pull request #5122 from adobe/randy/issue-5105

Looks good.  I did a quick review of shortcut key commands.  Tried out a sampling of about ten of them.  Didn't see any that would be negatively affected by a dismissal of a pop up.  Works for Context Menus, Code Hints, and Project Tree popup menu.