HUGE refactoring:

HUGE refactoring:
-Accounts are now handled by a pretty Account class.
-Keys inputs are now handled the Input class (with static methods) and use directly SDL, no more #define MAC_CRAP
-For that I had to add thread for two things:
	-the entername field
	-the key configuration
Maybe when the menu system will have been cleaned up (reorganized) the threads won't be needed anymore.
This commit can read old Users files, but not completely old config.txt files (you'll have to reconfigure keyboards bindings)