Fury of Xuen rppm update & assa t16 4pc tuning

Updated fury of xuen to latest rppm values and now the proc has different rppm values dependent of the spec like the legendary meta gem.

small tuning of the assa t16 4pc. It considers now that mutilate gives in a single hit 2 stacks. No real change to EP. Also moved the calculation out of the main loop because mastery has no impact on the cycle.