Two-player enhancements

A few updates for this game.  After some play testing, it would seem that the two-player mode devolves into a button-mashing mess.  That was the most important part of the game that needed to be tweaked, but there are other modifications.  Summary of changes:

1) Two-player mode reversal system has been retooled.  Instead of a simple 0.25-second window for the loser of a grapple to react, there is a 0.5-second hit-the-spot-nearly-exactly window.  This means that button-mashing will not let you reverse a grapple--you have to nail the edge of the half-second window nearly exactly, and the winner of the grapple can also try to do this to stop you.  So you CAN still reverse, but it's much more challenging.  Timing should be rewarded, not desperation.

Note that the one-player mode has not changed the reversal system--it remains the same as before.

2) Two-player mode has a higher overall damage multiplier for both sides, making matches last less time.  Some had thought two-player matches ran a bit long.

3) Two-player handicaps were woefully unbalanced.  The advantage given the player with the handicap is much more subtle now, with more emphasis on damage multiplier (somewhat fair) than grapple timing (much less fair).

4) Awkward collision logic fixed when a clothesline "passed through" a cartwheel kick; the cartwheel definitely knocks down the clothesline now.

5) After controller input registered, "colored button letters" replace the original keyboard hints.