Restored Zombie model addon

UPDATE: Fixed scaling issue on die_headshot2

Fixes the retail zombie model back to it's intended look. When Valve was fixing the scaling on their NPCs so they'd match their sight with the player's camera viewpoint, they messed it up on the zombie, scaling only the skeleton, leaving us with the slender looking zombie we all know and love. This model fixes that, along with a few improvements. Based on Chuck Jone's render

What I've done so far:

-Fixed the zombie's proportions back to normal by reverting the original value Valve used on the .qc file
-Fixed idle1's origin (used to be a little lower than usual)
-Recompiled the model with Day One's textures (slighty higher-res than retail's) and with Sven's compiler for better texture quality.
-Remade most of the UV's to avoid stretching and/or seams.
-Tweaked the coloring on the skull markings from the headcrab texture so it looks less forced.