set default minumum player count for multi column layout to 4

[ebbit1q]

fixes #3533
does not change existing settings

[ctrlaltca]

Looks fine to me. Forcing the change on existing users would be too much.

[Insertcleverphrasehere]

'forcing' wouldn't be accurate, they are free to change it back. But nothing will change unless we make a bump and shift everyone to multi column layout for 4. People will be free to change it back to 5 if they want, but if we want to create a unified system without lots of conflict, we need to update all the clients.

(If we don't then new players won't know why other people are piling stuff to the right because they don't know that a lot of other players will still be on non-multi column layout).

Perhaps a popup indicating what has changed and how to change it back if they don't like it might make it more palatable to update everyone's settings all at once?

[ZeldaZach]

Seems like a lot of effort on our parts for a minimal change imo, but maybe we can use this as an abstract method to update settings on the fly (see the URLs I introduced that @ctrlaltca modified with the new XML format). We can inform the users "OLD" and "NEW" and they can choose to revert our change.

[ebbit1q]

People don't like change, simply put.

[Insertcleverphrasehere]

Zach's suggestion sound's like it would work fine.