v2410

Ability:
-Added TestCustomCombatConditions Property to AbilityCriteria -- this is
set to true only when none of the normal combat are valid but the custom
combat criteria is. This allows the ability to continue to the custom
testing.
-Line of Sight conditions is now its own method which allows both
cluster and single target conditions to add LOS condition.

Avoidance:
-Removed Spore as avoidance -- (not the actual damaging one!)
-Poison Gas from Friendly Sources will be ignored now.

Destructible:
-Obstacles now obey the destructible range setting.
-When searching for an ability to use, ranged abilities will no longer
check object intersections during LOS.

Items:
-Removed AllowWalk from the LOS Testing (This was causing items to be
skipped.. I.E. Potions)

Unit:
BeingIgnoredDueToClusterLogic no longer checks if object is special.
When checking last health change it will now use the object
LastHealthChange property instead of the global one.