Introduced state FREEZE_VERSION for freeciv branches. That's the state between bumping
the version number and releasing first beta.

See patch #4512


git-svn-id: svn://svn.gna.org/svn/freeciv/trunk@24520 a0f10bec-cc02-0410-94fc-a9cfff90b4cd
Consider tile label changed also when its contents have changed, not just when
its state of existence has changed.

See bug #21657


git-svn-id: svn://svn.gna.org/svn/freeciv/trunk@24522 a0f10bec-cc02-0410-94fc-a9cfff90b4cd
Fixed selection of client settings file for development versions.

See bug #21698


git-svn-id: svn://svn.gna.org/svn/freeciv/trunk@24525 a0f10bec-cc02-0410-94fc-a9cfff90b4cd