[freeciv-ai] small unit move cleanup

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

This encapsulates handle_unit_move_request calls in ai code behind the a
packetable interface. I intend to move the ai ugliness in the
aforementioned function to this new function later.

I also intend to fundamentally rewrite the goto interface, merging
goto_route_execute and do_unit_goto, since they have lots of duplicate
code and do lots of stupid things. My idea is that the best way to do this
is by making a common goto_execute which takes two callback functions by
reference, that are called if the goto_execute encounters enemy units in
the open or enemy cities, respectively.

Please comment if you find anything objectionable in this.

Yours
Per

aimovecleanup.diff
Description: Text document