feature: support timestamped 0183 playback with Multiplexedlog

[tkurki]

Previously 0183 playback was output with current time timestamps in
deltas. This commit adds the timestamps to the deltas that 0183 parser
emits. This assumes that 0183 parsing is synchronous so that
the timestamp stored when calling parser.write will be the correct one
when 0183 parser emits deltas.

[tkurki]

Ping @fabdrol @joabakk I assume the new 0183 parser will be synchronous as well (not doing setImmediate or nextTick or something else magical).

[fabdrol]

@tkurki new parser uses promises - because it makes the main code more robust against unhandled exceptions in hooks / parse errors - and also because it means a hook could be async, should that be required for whatever reason.
However, that does mean that the timing will be different than purely synchronous code. If I remember correctly, (native) promises that resolve immediately execute after nextTick but before setImmediate on the event loop.

If I understand your comment, you assert that this is problematic in cases where the timestamp is generated by the parser - i.e. when a sentence doesn't have a timestamp of its own (either in the tag block or in the sentence). One option would be to generate a timestamp in the initial (synchronous) call to parse(), then pass this along to the actual hook.