Core/WorldSession: Mitigate DoS attacks

Mitigate DoS attacks like one explained in #10555 by processing a limited number of packets at each WorldSession::Update() call, allowing other WorldSessions to be processed.
100 packets in a single update sound like a reasonable amount.
Updated all values of `gender` column in `creature_model_info`.
Scripted/ScarletMonastery: Fix crash for headless horseman
Core/Creature: Added log/change back to default speed for speed walk / run = 0 (Speed is never zero)
Core/Object: Added more information for MovePosition log
Core: Fix warnings
Merge branch 'master' of https://github.com/TrinityCore/TrinityCore into teste2

Conflicts fixed:
	src/server/scripts/EasternKingdoms/ScarletMonastery/boss_headless_horseman.cpp