Fixed wrapping of next identity number counter. Also increased max number of
identity numbers to 250000

Reported by Anonymous

See bug #21950


git-svn-id: svn://svn.gna.org/svn/freeciv/trunk@25556 a0f10bec-cc02-0410-94fc-a9cfff90b4cd
Transmit road move_cost as signed value over the network.

Reported by Jacob Nevins <jtn>

See bug #22297


git-svn-id: svn://svn.gna.org/svn/freeciv/trunk@25559 a0f10bec-cc02-0410-94fc-a9cfff90b4cd
Generalized the check that workers cannot be building extras conflicting with
each other simultaneously to the same tile. It used to be hardcoded to prevent
simultaneous irrigation and mining.

See bug #22034


git-svn-id: svn://svn.gna.org/svn/freeciv/trunk@25560 a0f10bec-cc02-0410-94fc-a9cfff90b4cd
Have only one Makefile.am for all of alien ruleset.

See patch #4925


git-svn-id: svn://svn.gna.org/svn/freeciv/trunk@25561 a0f10bec-cc02-0410-94fc-a9cfff90b4cd