adds some features to Panels

**selectPanelByName()** and a way for owned components to listen for **onPanelActivate** events
removing notification code for coming changes; fixed unsafe loop for selectPanelByName
refined selectPanelByName
Merge pull request #4 from sugardave/panels-extra

adds some features to Panels

Reviewed-By: Ben Combee (ben.combee@palm.com)