Get the FREEZE version modpacks from the stable version URL.

See patch #4522


git-svn-id: svn://svn.gna.org/svn/freeciv/trunk@24538 a0f10bec-cc02-0410-94fc-a9cfff90b4cd
Play either "music_victory" or "music_defeat" when game ends.

See patch #4519


git-svn-id: svn://svn.gna.org/svn/freeciv/trunk@24540 a0f10bec-cc02-0410-94fc-a9cfff90b4cd
Added concept of "Culture", same as value of "Performance" effect of cities.
Currently culture affects player score only.

See patch #4019


git-svn-id: svn://svn.gna.org/svn/freeciv/trunk@24541 a0f10bec-cc02-0410-94fc-a9cfff90b4cd
Added missing files of patch #4019


git-svn-id: svn://svn.gna.org/svn/freeciv/trunk@24542 a0f10bec-cc02-0410-94fc-a9cfff90b4cd