Add a simple Application subclass which starts a UI mainloop.
Merge remote-tracking branch 'origin/master' into feature/gui_application
Update CHANGES.txt
Fix comments.
Fix comment so sphinx can use it.
Fix example to listen for application start rather than plugin start.
Change what event we're listening to.
Fix up documentation.
Merge pull request #34 from enthought/feature/gui_application

Add GUIApplication class