Drag and Drop Videos

This adds the ability to drag and drop youtube and vimeo videos to a factory and have it turn into an embedded video. Drag the location item (not the tab) for either player. Or drag youtube/vimeo video thumbnails from the google search result pages.


* Centralize drop event decoding in lib/drop and refactored lib/factory to use it.
* Improved drop failure handling (punt) so as to simplify improving drop patterns.
* Modified lib/plugin to not be so alarmist when plugins (like video) are missing.
* Added patterns to lib/drop for chrome/google centric url formats.