And added an event called "event_queue_flush_point" to mark where that
occured in the event stream. The FAF now uses an explicit event queue
flush instead of buffering input in order to wait for a file handle to
be returned from script-layer.
This reverts commit fc267d010d.
There were some diffs caused by this in external test suites I'm
unsure about, I'm going to go over optimizations more closely in
a different branch.
When a file handle is needed and the last event in the queue is also
a get_file_handle event with the same arguments, instead of queueing
a new event, just remember to cache/re-use the resulting handle from
the previous event. This depends on get_file_handle handlers not
changing global state that is also used to derive the file handle
string.
Versus from synchronous function calls, which doesn't work well because
the function call can see a script-layer state that doesn't reflect
the state as it will be in terms of the event/network stream.
