Bug Fix & Additional System Tweaks

Update 7/25/2014:

- Applied a fix for an issue which would sometimes show "PvP reward
error (code 2)" during PvP rewards. Please contact Whim if you see
this error pop up again. Thank you! =)

- Adjusted player rank calculations to more properly correlate to
overall power level.

- Minor tweaks to Invasion balance. We will look into hiring a
deputy to assist Christof during the enrollment process. =)

- The full prevention for toggling player killable has been
re-instated.