Nerf Rapid Strike

Currently the Rapid Strike technique is too good, leading to people not wanting other techniques on their weaponry because that reduces the chance they'll trigger a rapid strike.

A speed_mult of 0.75 is an effective 33% increase in DPS, as opposed to the current 100% increase in DPS.

Based on a request made in the forum: http://smf.cataclysmdda.com/index.php?topic=6709.0