Core/DBLayer: Comment out MySQL client/server version mismatch warning

MySQL version above 5.1 IS required in both client and server and there is no known issue with different versions above 5.1
Core/NPCs: Fix some equipment issues introduced with 028c72a9f2c606e8af3

Also changed equips defaults to 0 (no equipment) instead of 1.

It seems that some parts of the original commit were reverted locally, my bad.
Core/Players: Allow players to log out in combat when they are in resting area (logout in rest area is instant by default, but not when in combat)
Core/Logging: Fix mem leak. Thanks to @Sar777 for the report
Core/Misc: Remove devel log msg that shouldn't have been commited
Core/Vehicles: Also remove mount auras for passengers not in charm seat

May fix related crashes:
Ref #9256 #9255
Core/Creatures: Set hover movement flag if bytes1 have hover flag and creature cannot fly
Core/Vehicles: Fixed accessing freed memory in Vehicle::RemoveAllPassengers - _pendingJoinEvents needs to be cleaned from events that had already executed or were aborted
Core/Vehicles: Minor cleanup in header file
Core/Vehicles: Corrected logging message format specifiers
Merge github.com:TrinityCore/TrinityCore