Allow any string in WrappedGameProfile(String, String).

We now accept any string in this constructor, to preserve 
backwards compatibility. But, we depreciate its use, as 
WrappedGameProfile(UUID, String) can be used in every Minecraft
version that supports a game profile.

There's also a new warning system that will identify the plugin 
that is using the depreciated method, and print its name to the 
console (at most once every hour).