[freeciv-ai] pre-patch to new settler code

["Per I. Mathisen" <per@xxxxxxxxxxx>]

As requested by Greg, I have ripped out the govt change code from the new
settlers code.

This patch combines three general changes from the newsettler patch (I
didn't bother splitting them up more, the changes are simple and the two
first do not change gameplay and the last is a one-liner):
  - Evaluate which government we want in the beginning of the turn, so
that we can use this information during the turn.
  - Add two functions to create and destroy virtual cities.
  - Build settlers for city founding even if this means stagnation of
growth.

Please look at & commit ASAP, or I will.

  - Per

newsettler_prepatch1.diff
Description: Text document