UPDATED: New Guild methods and core support

CORE:
- ADDED: ChangeMemberRank() core support.
- ADDED: SendGuildInvite() core support.
- ADDED: Added TeamId enumerator.
- MOVED: Moved SessionMap outside of World class so LuaEngine can
interract with it. Possibly change in future?

LuaEngine:
- ADDED: GetLeader() Guild Method added.
- ADDED: SetLeader() Guild Method added.
- ADDED: GetBankMoney() Guild Method added.
- ADDED: DepositBankMoney() Guild Method added.
- ADDED: WithdrawBankMoney() Guild Method added.
- ADDED: GetMemberCount() Guild Method added.
- FIXED: GetPlayersInWorld() Global method fixed.
- FIXED: GetMembers() Guild method fixed.
- FIXED: ChangeMemberRank() Guild method fixed.
- FIXED: GetGuildName() Unit method fixed.
- FIXED: GetGuild() Unit method fixed.