Added progress bar to Qt modpack installer

See patch #4341


git-svn-id: svn://svn.gna.org/svn/freeciv/trunk@23875 a0f10bec-cc02-0410-94fc-a9cfff90b4cd
Removed nuke_contamination ruleset setting as redundant.
Changed rulesets that used to have nuke_contamination set
to "Pollution" to have "Fallout" as second cause for "Pollution"
extra instead.

See patch #3957


git-svn-id: svn://svn.gna.org/svn/freeciv/trunk@23877 a0f10bec-cc02-0410-94fc-a9cfff90b4cd
Rename 'is_available' property of nations to 'is_pickable' to better
reflect its purpose, and make it a network/client specific notion -- on
the server we now track individual reasons why a nation can't be picked
(currently only lack of a start position). No functional change.

See gna patch #4304.

git-svn-id: svn://svn.gna.org/svn/freeciv/trunk@23878 a0f10bec-cc02-0410-94fc-a9cfff90b4cd
The Xaw client races dialog didn't honour is_pickable, so included
nations that couldn't be chosen due to a start position restriction.

See gna bug #21361.

git-svn-id: svn://svn.gna.org/svn/freeciv/trunk@23879 a0f10bec-cc02-0410-94fc-a9cfff90b4cd
Refactor Gtk clients' nation selection dialog, with the following aims:
 - Prepare for the set of pickable nations to change while it's up
   - (and hence, the set of nation group tabs in the notebook; this
     avoids empty tabs in scenarios restricted to a subset of nations)
 - Restore the player's current nation settings, leader name etc when
   the dialog is popped up
 - Highlight the selected nation correctly when changing group tabs

See gna patch #4347.

git-svn-id: svn://svn.gna.org/svn/freeciv/trunk@23880 a0f10bec-cc02-0410-94fc-a9cfff90b4cd
Replace the old 'soft' notion of 'nation sets' with a new, stronger
notion, controlled by a new server setting 'nationset'.
Nations outside the current set can no longer appear in the game in any
circumstances, and the number of players is limited by the number of
available nations. In standard rulesets, the 'nationset' setting must
now be changed to access any nations outside the "core" set.
Clients only minimally updated: if the nationset is changed, any nation
dialog that is up at the time will be popped down.

See gna patch #4348.

git-svn-id: svn://svn.gna.org/svn/freeciv/trunk@23881 a0f10bec-cc02-0410-94fc-a9cfff90b4cd
Fully support nation sets in the Gtk clients.
Add a control to the Pick Nation dialog to select a nation set, and
update the dialog when the nation set changes without popping it down.

See gna patch #4349.

git-svn-id: svn://svn.gna.org/svn/freeciv/trunk@23882 a0f10bec-cc02-0410-94fc-a9cfff90b4cd
Removed unnecessary Farmland extra completely from civ1 ruleset.

See patch #4342


git-svn-id: svn://svn.gna.org/svn/freeciv/trunk@23888 a0f10bec-cc02-0410-94fc-a9cfff90b4cd
Updated include lua to version 5.2.3

See patch #4343


git-svn-id: svn://svn.gna.org/svn/freeciv/trunk@23889 a0f10bec-cc02-0410-94fc-a9cfff90b4cd
Fixed SDL2-client compilation.

Syy bug #21368


git-svn-id: svn://svn.gna.org/svn/freeciv/trunk@23891 a0f10bec-cc02-0410-94fc-a9cfff90b4cd