Refactors LimitedAmmo to AmmoPool.

Removes Reloads trait.

This enables adding multiple AmmoPools via @ differentiators and
Name which adds the possibility to assign each armament to a specific
ammo pool.

Furthermore, this moves all Reloads functionality onto AmmoPool.

Now a combination of all three is possible on a single actor: no limited
ammo, limited ammo that can reload on its own, and limited ammo which
needs to be reloaded at a rearm actor.

Additionally moves RearmSound from Minelayer to AmmoPool.

mods/d2k/rules/aircraft.yaml

@@ -157,7 +157,7 @@ orni.bomber:
 		RepairBuildings: repair
 		RearmBuildings:
 		Repulsable: False
-	LimitedAmmo:
+	AmmoPool:
 		Ammo: 5
 	RenderUnit:
 		Image: orni