Merge with vanilla 2.2 and  2.2.0.1 beta

Hi Superpat,

Here's a compatibility patch for modified files from vanilla with patch 2.2 and 2.2.0.1 beta:
- Merge religion icon sprites
- Use is_unique to simplify minor_titles checks
- build_cost replaced by gold_cost in buildings.txt

Some stuff not handled here, but noticed during merge:
- new Lombard culture impact on hellenic (CB, ...)
- viceroyalty localization for Hellenic / Roman culture