Fix some bugs with mega evolution graphics
- Don't play the forme change animation when switching in.
- Fix interaction with illusion in the base forme (http://replay.pokemonshowdown.com/almostanyability-117184227 Turn 11)
MegaEvo: tell the client that the change is permanent
Obviate -formechange in mega evolution
Merge pull request #909 from Slayer95/megaevo

Fix some bugs with mega evolution graphics