Core/Vehicles

* Fixed vehicle orientation on transports
* Fixed exiting vehicles on moving transports
Core/Instances: Fix Instance binding

Fix players not being bound to instance if the group was disbanded before killing any boss.
Fixes #437
Scripts/Halion: Fixed Soul Consumption's pull effect.

Thanks to Winterfell for pointing out the issue.
Core/Entities: correct creature damage, offhand damage should work too
* todo: some creatures need dmg_multiplier update in creature_template
DB/Spells: remove duplicate/invalid entries from spelldifficulty_dbc
* For new entries: use spellid0 as id to avoid conflicts with dbc file
DB/Spells: correct more spelldifficulty_dbc entries
* add log message to find wrong entries
Core/Threading: Handle CMSG_ZONEUPDATE only in WorldSession update - changing zones triggers changing chat channels, what is not a thread safe operation
Scripts/HoS: update Maiden of Grief
Merge commit '95f14f921b0dd293e2b7a89718f7b181c5c61948'