FLOE-194: Implement match confirmation dialog.

JIRA: http://issues.fluidproject.org/browse/FLOE-194
I predict leakage risks with both of these listeners in the case the dialog has been destroyed. The deregistration semantics for globalDismissal are that providing null as the func argument will deregister the listener. As for the iframe listeners, you should most likely namespace them and clear them out when the dialog component is destroyed.
Note that the dialog.dialog("isOpen") test is not safe since jQuery UI is insufferable about the semantics of destroyed components and nodes and will trigger a hard error on trying to access a jQuery UI instance which has been destroyed. You are safer to eliminate the listeners yourself in response to dialog close than to guard them internally like this.