Extend the lag module to monitor timer drift

Suggested by Hakaku a long time ago:

Cheating-wise, I would suggest that the server keep track of a player's timer drift (and spec them). Higher than 25 or lower than -25 (in *einfo) is an indicator that a player is either of three: 1) cheating, 2) lagging too horribly to play anyways, 3) in an odd time zone (which shouldn't happen)