3 new functions added to `y_weapondata`

[DEntis-T]

Reopen the request #609.

[DEntis-T]

@Y-Less

[DEntis-T]

I've asked you about five times why "types" are different to "slots". They map 1-to-1, so there's absolutely no need for two things giving the same information. Why do they exist? What do they add? Where does the idea come from? Why does just using slots not work?

They don't map 1-to-1; look:

stock WeaponType:Weapon_GetType(weaponid)
{ 
	return WeaponType:(Weapon_GetSlot(weaponid) - 1);
}

There's not a slot 0.