Fixed SendAddonMessage issue.

This fixes GM's not being able to send/receive addon messages through the whisper channel while accepting whispers are turned off.
Core/Misc: Fix crash in ticket creation

Fix a crash happening with malicious CMSG_GMTICKET_CREATE packets.
Core/SAI: Prevent nullifying damage, because of player damage requirements
Fix various warnings. The core, the scripts and the tools now compile without warnings with -Wall -Wextra -pedantic.

-Fix warnings from -Woverflow on implicit constant conversion.
-Fix warnings from -pedantic.
-Fix warnings from -pedantic.
-Fix warnings from -Wformat.

Two minor changes in addition :

-Replace a defined value equal to 2^31 - 1 by std::numeric_limits<int>::max().
-Remove useless null-check on pointer returned by new. New doesn't returns nullptr on failure, it throws std::bad_alloc.
Remove changes in dep file.
Core/SAI: Clear UNIT_STATE_EVADE immediately if we're about to follow a target on EnterEvadeMode (MoveFollow does not clear evade)
Contrib: Added an updated version of the configuration file merger tool.

This one lets you choose which value to keep between the two configuration files.
Make sure to carefully read the file's lines 3 to 9 to make sure you don't misuse it and get back at me later raging.
It is not exactly as I would like it to be, but current state will have to do.

You can try it out live at: http://tinyurl.com/kzxmrlm
Core/GameObjects: fixed instant reset of gameobjects after activation
Core/Calendar: Use single database transaction for adding multiple invites when creating new event
Core/Calendar: Align max amount of Players to be invited to Client limits

Limit the max amount of Players to be invited to a Calendar event to 100, same limit as the one in the Client
Fixed build without pch
Shared/Database: Increase Database Worker Pool queue size

Increase DatabaseWorkerPool queue size from the default 16KB to 8MB to avoid blocking the caller thread when queuing an async statement/transaction.
Core/Warden: Fix crash

Fix crash with empty CMSG_WARDEN_DATA packets
Shared/Packets: Handle crash by throwing an exception instead

Throw a ByteBufferException when trying to access the first element of an empty ByteBuffer class
Merge pull request #12070 from Trisjdc/more_sai

Core/SAI: Prevent nullifying damage, because of player damage requirements
DB/Creature: Highlord Darion Mograine - Restore Shadow's Edge gossip

By Foldy, closes #12079
Merge pull request #12071 from Praetonus/warnings

Fix various warnings.
DB/Creature: Ethereal Soul-Trader

By Foldy, closes #12080 updates #4152
DB/Gameobject: Thunderbrew Lager Keg

By Foldy, closes #12078
DB/Misc: Nesingwary Lackey Ear

By nelegalno, closes #8624