Zoom in/out of history charts  - By JackRainy

Removing old buildings on enemy capital (when not last city) no longer crashes

Liberating city with multiple units in it no longer errors

By SomeTroglodyte:
- Fixed ruleset error crashes
- Fixed loading of mods with unconventional names
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By SeventhM:
- Modding: Allow Great People to have different counters
- Tech column validation for mods
- Solved crashes from undefined building costs

Ensure more unit uniques work - By xlenstra