Add frame around city dialog output info popup.

See #16243

Fixed crash when building base that conflicts with another base type to tile
where is no previous base.

See #40627

Typofix

Check for NULL ping timers when closing a connection.

- Add timer_list_iterate macro.
- Check for NULL connection in close_connection().
- Check for NULL timer in free_timer().

See #40605

Reported by: Marko Lindqvist

Make the tired attack penalty optional via the ruleset.

- The new game ruleset field tired_attack in the
combat_rules section controls whether units that
have less than a full move left will have their
attack strength reduced when they attack.
- The server and default ruleset disable it.
- It is enabled in the civ1 and civ2 rulesets.

See #40591

Fix river generation for island generator.

See #15947

Patch by: Brendon Oram

83% done