Bug#699296: freeciv: New upstream version 2.3.3 available

[Jacob Nevins]

Package: freeciv
Severity: wishlist

Notably, this fixes the security issues of #696306, as well as a number
of other bugfixes <http://www.freeciv.org/wiki/NEWS-2.3.3>.

This would also be an opportunity to fix #677891.

(Even if Debian's in freeze, would getting this into unstable allow it
to trickle into Ubuntu, possibly for 13.04?)