Core/Guild: Fix Guild validation crash on start up

Partially revert 58ec4e531914121144b6f852e3abf27cbb2f6fc4 and increment GuildStore iterator before validating Guilds. This is required because Guild::Validate() removes the Guild from GuildStore if invalid.
Closes #8363
Merge pull request #10722 from jackpoz/guild_startup_crashfix

Core/Guild: Fix Guild validation crash on start up
DB/Misc: Fix few startup errors
Core/Achievements: Converted save queries to prepared statements
Core/Vehicles: Add vehicle_seat_flag_unk18 (0x20000) to seat.IsUsableByOverride

Exact definition still needs to be researched
Scripts/Commands: Check if creature entry is valid before attempting to spawn (fixes unneccessary error in logs)
Update DBCStructure.h
Core/Commands: Fix .debug send opcode freeze if file dont exists.
Merge pull request #10729 from xjose93/DebugSendOpcodeFreeze

Core/Commands: Fix .debug send opcode freeze if file dont exists.
Core/Spells: add an other condition to SpellInfo::NeedsToBeTriggeredByCaster to correct spells with are wrongly triggered by target instead of caster
- convert archavons rock shards to spellscript (now it works properly)
- add a spellscript for one spell that can't be corrected by this (and delete the sai hack, now i uses the correct spell)
Scripts/YoggSaron: fixed rewarding loot
Fixed build
-.-
Core/SAI: Fix typo (i blame germans laziness)
Merge branch 'master' of github.com:TrinityCore/TrinityCore into 4.3.4

Conflicts:
	src/server/game/Achievements/AchievementMgr.cpp
	src/server/game/Spells/SpellMgr.cpp
	src/server/scripts/Commands/cs_npc.cpp