Greeting stats translated correctly in notifications

Multiplayer screen correctly handles errors when downloading mods

"Cannot attack" accepts "vs" conditionals

By SeventhM:
- Add a field for global unit uniques 
- Allow building improvements on terrains that only allow some improvements when it has multiple uniques 
- Add conditional for when you aren't in a golden age 

Added an UniqueType to Found puppet city. - By Emandac

By itanasi:
- Set Avoid Growth=false on city capture