Added a variety of test listeners for the frame so that we can observe events the frame receives, and a flag to toggle whether to add the listeners.  Make sure to dispose of the frame graphics context if it becomes invalid.  Removed code to prevent adding a frame participant more than once since the observer list now handles that for us.
Added a variety of test listeners for the frame so that we can observe
events the frame receives, and a flag to toggle whether to add the
listeners.  Make sure to dispose of the frame graphics context if it
becomes invalid.  Removed code to prevent adding a frame participant more
than once since the observer list now handles that for us.


git-svn-id: a1a4b28b82a3276cc491891159dd9963a0a72fae@2148 542714f4-19e9-0310-aa3c-eee0fc999fb1

threerings/narya,threerings/narya,threerings/narya,threerings/narya,threerings/narya