Log Message:
Update freeciv to 2.5.3

Many changes listed in:
http://www.freeciv.org/wiki/NEWS-2.5.3
http://www.freeciv.org/wiki/NEWS-2.5.2
http://www.freeciv.org/wiki/NEWS-2.5.1

We were after:
     * Build fixes:
          + Re-generating the configure script could fail on recent OS
            distributions due to a clash with the system supplied
            glib-gettext.m4. This did not affect most users, who would
            build with the configure script supplied in the tarball.
            GNA#24379