Blind, Dazzle, EE, Purge rebalance

Rather than opting to nerf Purge, we determined the problem is really
the incredible vulnerability players have to Blind and Dazzle when they
lose Eagle Eyes.

Eagle Eyes formerly reduced Blind&Dazzle durations by up to 50%. I
removed that function and simply cut Blind&Dazzle durations by 50%.
Eagle Eyes is still a great buff that adds damage and offense for bows,
as well as resisting blind 5% and dazzle 10% of the time.

However, players should have a much more enjoyable combat experience
without Blind&Dazzle completely shutting them down for 15-20 seconds per
cast.

This makes Purge much less devastating by proxy. I plan to add a Detect
Invisible ring to make up for the other major problem with Purge
(removing DI while using an invis ring).