Core/LFG: Minimum item level in Wotlk heroic dungeons

WotLK Heroics, beside Trial of the Champion, Pit of Saron, Halls of Reflection and The Forge of Souls unlock with an average item level of 160.
Also Trial of the Champion (normal) and The Forge of Souls (normal) unlock with an item level of 160.

http://www.wowwiki.com/Dungeon_Finder?oldid=2404648#Wrath_of_the_Lich_King_dungeons
Core/Groups: Fixed UnitIsPartyLeader lua function
Core/Spells: Fixed AoE damage reduction auras, original patch by @Unholychick
Merge pull request #11095 from gerripeach/pull_request3

Core/LFG: Minimum item level in Wotlk heroic dungeons
Rename 2014_01_21_world_access_requirement.sql to 2014_02_04_00_world_access_requirement.sql
Core: Add rest of checks from SendListInventory to BuyItemFromVendorSlot
DB/SAI: Fix Dire Maul entrance levers

Updates #6298
Core/Achievements: Implement criteria type ACHIEVEMENT_CRITERIA_TYPE_ON_LOGIN and criteria requirements ACHIEVEMENT_CRITERIA_REQUIRE_NTH_BIRTHDAY and ACHIEVEMENT_CRITERIA_REQUIRE_KNOWN_TITLE. Fixes anniversary achievements.

By @Schmoozerd
Core/Achievements: Use ACE_OS::localtime_r instead of localtime in my previous commit for thread safety.

Thanks to @Shauren
Merge pull request #11568 from Rochet2/VendorChecks

Core: Add rest of checks from SendListInventory to BuyItemFromVendorSlot
Core/Auras: Implemented SPELL_AURA_MOD_COOLDOWN

Closes #9671
Authserver / Worldserver: Fix warnings about unused variables
Remove whitespaces from previous commit
DB/Gameobject: Fix Dire Pool

Closes #9893
Core/Entities: allow interaction with gameobject questgivers if player can take or return quests

Closes #11269
Closes #8898
Closes #10204
Closes #11410
Closes #7053
Closes #6189
Closes #9474