Weapon error messages incorrect

[Ollieollieolllie]

https://github.com/SachaOropeza/AH64D-Project/issues/52
Currently, LOS INVALID is used for the following reasons:

• If terrain obscures the line of sight to the target (no matter of the weapon selected)
• If another object obscures the line of sight of the selected target, and the selected weapon is not a Hellfire AGM-114L
• If the target is more than 30-degrees off the nose of the aircraft to the left or right.
  Even when an error is occurring, the player is currently able to fire.

However, it should be split up into the following error codes:

Error code	Condition	Prevents Firing
COINCIDENCE	The targeting position is not the same position as where the gun is pointing	Yes
AZ LIMIT	The gun is limited left-right, but TADS/HMD is pointing further	Yes
EL LIMIT	The gun is limited up-down, but TADS/HMD is pointing further	Yes
BAL LIMIT	The target is outside of the ballistic limit of the weapon computer (for the gun >4.2km)	No