Allow city filters to be multifilters and not throw ruleset errors

Resolved  - Korean science boost only applies for buildings *in capital*

Further split between different road automations, some cleanup of the roadTo automation (but not enough, still pretty bad)

Separated road automation to a separate file, but actually we have 2 completely different functions here, not sure if requires subdivision

By SeventhM:
- Avoid crash from city combantants 
- Remove cache for nonstandard tile damage 

ThreatManager improvement  - By tuvus