Battle backgrounds gen 3 + 5
Battle backgrounds gen 3 + 5

Adding in the gen 3 bg, and fixing it so that gen 5 can use the rotating backgrounds that it could before.

Preview: http://i.imgur.com/qQB0mj5.png
asgdf/Pokemon-Showdown-Client,QuiteQuiet/Pokemon-Showdown-Client,QuiteQuiet/Pokemon-Showdown-Client,asgdf/Pokemon-Showdown-Client,submindraikou/Pokemon-Showdown-Client,submindraikou/Pokemon-Showdown-Client,panpawn/Gold-Client,submindraikou/Pokemon-Showdown-Client,asgdf/Pokemon-Showdown-Client,Zarel/Pokemon-Showdown-Client,sirDonovan/Pokemon-Showdown-Client,panpawn/Gold-Client,Zarel/Pokemon-Showdown-Client,sirDonovan/Pokemon-Showdown-Client,Zarel/Pokemon-Showdown-Client,QuiteQuiet/Pokemon-Showdown-Client,sirDonovan/Pokemon-Showdown-Client,panpawn/Gold-Client,Zarel/Pokemon-Showdown-Client,QuiteQuiet/Pokemon-Showdown-Client,sirDonovan/Pokemon-Showdown-Client,asgdf/Pokemon-Showdown-Client