Fix Male Assassin unable to use the Sniper Rifle.

Partially fixed the Stukabat being unable to move when target is unreachable.
Removed zombie/gonome bullet resistance.
Add Global Model Replacement and Global Sound Replacement.
Update Tier milestones.

src/dlls/hassassin.cpp

@@ -256,7 +256,7 @@ void CMHAssassin :: Precache()
 
 	PRECACHE_SOUND("debris/beamstart1.wav");
 
-	m_iShell = PRECACHE_MODEL ("models/shell.mdl");// brass shell
+	m_iShell = PRECACHE_MODELINDEX("models/shell.mdl");// brass shell
 }