Playground request - ivar references to

This doesn't hurt me enough to try to do it myself yet, but one thing I feel it would be natural to do in Raw view would be to have a <references to> context menu item for the instance variables, or even better like the debugger have <List methods using...> and <List methods storing into...>.  

btw I notice those last two actually are missing from GTDebugger and I miss them :).

(or am I missing something functionality?)

cheers -ben