Fixed custom flinching and takeover animation not working properly in multiplayer.

Made BMCE zombies also able to flinch using the same animations as classic zombies.

Implemented classic zombie / zombine locational flinch animations, triggered by shooting at specific body parts (legs, arms). Only works if Sabrean's Zombie Mod is installed.

Any npc with the class "npc_citizen" no longer randomly becomes a zombine when infected by a standard headcrab.

Fixed fast zombie climbing mechanic, it no longer freezes after reaching the top of a wall.

Added new lua hooks to modify some of the behavior in this mod:

headcrabtakeovercreatezombiehook - (zombie, zombieskin, victimmodel, victimskin)
headcrabtakeovercreatezombietorsohook - (zombie)

The two above will run immediately after a headcrab transformation / a zombie becomes a living torso through the functions added by this mod.

headcrabtakeovershouldzombine - (victim, attacker)
headcrabtakeoverforcezombine - (victim, attacker)

The two above will run before deciding if the resulting zombie from a headcrab transformation should be a zombine.
The first one can be used to disallow the zombie from randomly becoming a zombine even if the victim wasn't a combine type enemy, while the second can instead force the zombie to be a zombine. Return "true" to achieve these effects.

The previously introduced BMCE compatibility now makes use of these hooks and continues to function the same exact way as before.