Core/Achiev: Warning if GM mode enabled (#1028)
Core/Achiev: Warning if GM mode enabled (#1028)

* Core: Achievements warning if GM mode enabled

Added a warning ingame and in console when you're a GM testing achievements (else it was confusing).
Added an extra type check in UpdateAchievementCriteria, ported from TrinityCore.
jokerlfm/azerothcore-wotlk,Helias/azerothcore-wotlk,mygithome002/azerothcore-wotlk,Nefertumm/azerothcore-wotlk,mygithome002/azerothcore-wotlk,Nefertumm/azerothcore-wotlk,Helias/azerothcore-wotlk,Helias/azerothcore-wotlk,Nefertumm/azerothcore-wotlk,azerothcore/azerothcore-wotlk,ShinDarth/azerothcore-wotlk,ShinDarth/azerothcore-wotlk,Nefertumm/azerothcore-wotlk,Helias/azerothcore-wotlk,mygithome002/azerothcore-wotlk,mygithome002/azerothcore-wotlk,ShinDarth/azerothcore-wotlk,azerothcore/azerothcore-wotlk,mygithome002/azerothcore-wotlk,Nefertumm/azerothcore-wotlk,mygithome002/azerothcore-wotlk,Helias/azerothcore-wotlk,azerothcore/azerothcore-wotlk,azerothcore/azerothcore-wotlk,jokerlfm/azerothcore-wotlk,jokerlfm/azerothcore-wotlk,azerothcore/azerothcore-wotlk,Nefertumm/azerothcore-wotlk,jokerlfm/azerothcore-wotlk,jokerlfm/azerothcore-wotlk,Helias/azerothcore-wotlk,ShinDarth/azerothcore-wotlk,jokerlfm/azerothcore-wotlk,azerothcore/azerothcore-wotlk