Core/LFG: Allow group bound to LFG instance to re-queue if someone leaves the party
DB/Quest: Return of the High Chief

Script http://www.wowhead.com/quest=12069 rather than the tusk just been permamently spawned on the ground
DB/Quest: All Hail Roanauk!

Script http://www.wowhead.com/quest=12140

Closes https://github.com/TrinityCore/TrinityCore/issues/3051
DB/Spells: Cleaned playercreateinfo_spell_custom table and added WoTLK class spells only

Current playercreateinfo_spell_custom table has very weird spells in it. I emptied table, created new character for each class, logon each class, learned every spell from trainer and then added rest spells from quests (for example, hunters' Tame Beast). After that I did a PHP script to get character's spells from character_spell table and insert them into playercreateinfo_spell_custom table.

This has all trainer spells and quest spells (if any) for 3.3.5!

Fixes #13509
Closes #13516