Make the Expanded Army List settings 0-1 in allied detachments

[nstephenh]

We get requests about expanded units in allied detachments from time to time.
If we turn on the settings to allow them to to be added to ally detachments this problem goes away.

Ensure the max per roster is still 1.

Consider renaming it to "list building settings" in case we want to add anything else to this box (campaign rules, etc).

[The4D6]

Not sure this needs to be done as the "expanded" units are considered legal by seemingly everyone and their dog, not sure we need to implement this