Began to implement user accounts using the database

I'm mostly just testing the waters at this stage, and i've left some debug
code in. There's no way to unload, delete, etc. the accounts, but that
comes later.

server/character_data.hpp

@@ -31,7 +31,6 @@
 struct CharacterData {
 	//metadata
 	int clientIndex;
-	std::string username;
 	std::string handle;
 	std::string avatar;