Core/Creature: Implemented negative levels for creatures having -1 as expansion
Core/Packets: Fixed player movement speed change packets
Core/Units: Updated byte order in UNIT_FIELD_BYTES_0 - fixes weird models

Closes #13648
Core/DBC: Move sPhasesByGroupStore and access method to DB2Stores

DB2Stores were not loaded yet at the old position.
Core/Packets: Added SMSG_MOVE_TELEPORT, SMSG_MOVE_UPDATE_TELEPORT, CMSG_MOVE_TELEPORT_ACK packets
Core: Fixed an old merge mistake
Core/Misc: Fixed some of the Coverity defects
Core/Game: Fix several warnings about wrong data types
Core/Game: Add missing default cases in switches
DB/GameTele: Added some Pandaria teleport positions.