Include in-game time in playback

[JamieGoodson]

Upon starting capture, grab current in-game time. On capture export, include this time in the mission meta-data.

Knowing the mission start time, and capture delay (e.g. 1 frame capture per second), we can calculate the game time in playback.

Potential issues: If game-time is suddenly changed (e.g. by Zeus or mission script), this will not be reflected in playback.