Build fix
SQL: Update auth_database.sql

It was missing an update to realmlist.gamebuild
DB/World: Update faction and unit_class to default values
Core/AccountMgr: Fix two typos when checking length of password

No real change, both MAX_ACCOUNT_STR and MAX_PASS_STR are currently 16
Core/Packets: Add a constructor to ClientPacket with expected opcode (asserted)

Also move all trivial packet constructors from .cpp to .h
Core/Packets: CMSG_CANCEL_TRADE handler
Core/Packets: CMSG_VIOLENCE_LEVEL handler
Core/Packets: CMSG_LOAD_SCREEN (LoadingScreenNotify) handler
Core/Packets: CMSG_NAME_QUERY (QueryPlayerName) handler
Core/Packets: SMSG_NAME_QUERY_RESPONSE (PlayerNameResponse) handler
Fix build
Warning fixes