Add sjs:events module

 - host events (either DOM element or EventEmitter depending on hostenv)
   can be wrapped by events.HostEvent, which is a subclass of cutil.Event
   with the same API.
 - events.Queue is an event queue supporting both host and cutil events

 - Removed sjs:xbrowser/dom.waitforEvent and sjs:nodejs/events.waitforEvent (replaced by sjs:events.waitforNext)
 - Removed sjs:xbrowser/dom.eventQueue and sjs:nodejs/events/eventQueue (replaced by sjs:events.Queue)
 - Removed sjs:nodejs/events module
Added code to copy event before emitting on IE
minor update to repl.sjs for new events API
renamed events.waitforNext -> events.wait
events: Added notes about event propagation
Merge branch 'mho' into event-refactor
Renamed cutil.Event -> events.Emitter, and HostEvent -> HostEmitter
Merge branch 'event-refactor' into mho

Conflicts:
	modules/surface/base.sjs
Doc fix