Activate "undo" and  "clrpaper" events

Hi,
I send the "undo" and  "clrpaper" events from bbb-apps, and remove shapes in Redis so that the new html5-client users won't get the deleted shapes while log in.
Also, when presenter in flex side draws a square, I send a Boolean data "square" to html5-client in order to enable the html5-client to see the square as well.

Thanks

Gary Deng