Ban Mega Mewtwo from both Smogon Doubles formats

why did it even get two anyway
Merge pull request #488 from Arcticblast/patch-2

Ban Mega Mewtwo from both Smogon Doubles formats
Ban Mega Mewtwos on Inverse Battle

Additionally, we should seek a way to automatically ban mega 
formes of those Pokémon banned on their normal forme.
Update Klefki base stats
Add Rage Powder message
Merge remote-tracking branch 'upstream/master'