Introducing the Character class.

With this new class the API user can fetch the basic character info.
Soon I will add support for additioal character info, like: Achivs, Titles
and etc.

Also I'm chaging the way that the API will work. I will refactor the classes
Auction_Requester and Item_Requester to be like the Character class. I don't
think that returning to the user a json/map is enough for a good API.

TODO:
 - Add tests for Character, BattleGroup,Class and Race
 - Refactor Auction_Requester and Item_Requester and its tests
 - Add an API in Character class to fetch the additional char infos