Support past gens in Dex
Support past gens in Dex

Now, like the server, it will be possible to use
`Dex.mod('gen5').getTemplate("Butterfree")` or the equivalent.

sirDonovan/Pokemon-Showdown-Client,sirDonovan/Pokemon-Showdown-Client,Zarel/Pokemon-Showdown-Client,Zarel/Pokemon-Showdown-Client,Zarel/Pokemon-Showdown-Client,sirDonovan/Pokemon-Showdown-Client,sirDonovan/Pokemon-Showdown-Client,Zarel/Pokemon-Showdown-Client