Fixes small bugs with models and adds 3 new models.
-p_m3 (muzzle flash used to appear in the middle)
-p_scout (muzzle flash also used to appear in the middle)
-w_ump45 (fixed small errors)
-p_shell, rshell, rshell_big, shotgunshell.mdl (fixed size issues)
-p_ump45 (originally non-existent)
-p_knife (matches deleted scenes!)