Updated shiny sprites

[justingolden21]

Updated normal and shiny sprites for blastoise, mewtwo, gallade, and diance megas. Blastoise was shifted a few pixels, mewtwos were missing consistent shiny sprites, as were gallade and diance.

Current normal:

Current shiny:

Sprites from showdown:

• https://play.pokemonshowdown.com/sprites/gen5-shiny/
• https://play.pokemonshowdown.com/sprites/gen5/

[justingolden21]

File diff shows the previously updated sprites as well. Not sure if you somehow merged only part of the changes last time or merged and then removed, but just a heads up. Let me know and I can revert those files.