CorbaEventDispatcher: rename TimedStructuredEvent → OutgoingTimedStructuredEvent and make static
CorbaEventDispatcher: move OutgoingTimedStructuredEvent class to its own file
CorbaEventDispatcher: reorder methods to reflect the order in which they're executed
CorbaEventDispatcher: minor cleanups
CorbaEventDispatcher: get rid of duplicate code for creating OutgoingTimedStructuredEvent instances