Add LookScale variable on weapon

This variable allows a weapon to set a custom look sensitivity multiplier without fiddling with FOVScale / DesiredFOV hacks.

src/g_game.cpp

@@ -757,6 +757,7 @@ static int LookAdjust(int look)
 		players[consoleplayer].ReadyWeapon != NULL)			// No adjustment if no weapon.
 	{
 		auto scale = players[consoleplayer].ReadyWeapon->FloatVar(NAME_FOVScale);
+		scale *= players[consoleplayer].ReadyWeapon->FloatVar(NAME_LookScale);
 		if (scale > 0)		// No adjustment if it is non-positive.
 		{
 			look = int(look * scale);

src/utility/namedef.h

@@ -1029,6 +1029,7 @@ xx(Kickback)
 xx(MinSelAmmo1)
 xx(bDehAmmo)
 xx(FOVScale)
+xx(LookScale)
 xx(YAdjust)
 xx(Crosshair)
 xx(WeaponFlags)

wadsrc/static/zscript/actors/inventory/weapons.zs

@@ -28,6 +28,7 @@ class Weapon : StateProvider
 	Ammo Ammo1, Ammo2;						// In-inventory instance variables
 	Weapon SisterWeapon;
 	double FOVScale;
+	double LookScale;						// Multiplier for look sensitivity (like FOV scaling but without the zooming)
 	int Crosshair;							// 0 to use player's crosshair
 	bool GivenAsMorphWeapon;
 	bool bAltFire;							// Set when this weapon's alternate fire is used.