added "leave" network-level event. removed code to block concurrent events of the same name (seems this should be a strategy thing?). started queueing events rather than having them supercede current event(s).
added "leave" network-level event. removed code to block concurrent events of the same name (seems this should be a strategy thing?). started queueing events rather than having them supercede current event(s).

cujojs/cola