Add screenshake on explosion.

dlls/ggrenade.cpp

@@ -64,6 +64,8 @@ void CGrenade::Explode( TraceResult *pTrace, int bitsDamageType )
 
 	int iContents = UTIL_PointContents( pev->origin );
 
+	UTIL_ScreenShake( pev->origin, 25.0, 150.0, 1.0, 750.0 );
+
 	MESSAGE_BEGIN( MSG_PAS, SVC_TEMPENTITY, pev->origin );
 		WRITE_BYTE( TE_EXPLOSION );		// This makes a dynamic light and the explosion sprites/sound
 		WRITE_COORD( pev->origin.x );	// Send to PAS because of the sound