#76 allow changeOwnership on null owned territory

[David Landry]

For some reason if a territory had no owner (null) and a changeOwnership trigger was used, nothing would happen. I see no reason to disallow this, and this is necessary to support the current 1914 map file because some neutral territories begin unowned and change ownership through a trigger when attacked.

I doubt anyone is relying on this behaviour in their map file so I don't think this will break any existing maps.

[Chris Duncan]

accepted and committed

as a side note, you can always make a "neutral" player (see mongolians in global 1940 as an example)