Allow rulesets to forgo capital city indicators entirely!

Default city for hexarealm does NOT have a question mark

Added ruleset validation for preferred victory type

By SomeTroglodyte:
- Mod checker reports some problems with texture atlases or their source images
- ImagePacker detects changed settings file
- Make random conditionals depend on turn

By tuvus:
- Fixed gold ruin not displaying notification
- AI worker build roads improvement