Add mssing unit to Royal Barracks.

All barbarian temples available for all barbarian factions.

- Added missing constructed images for barbarian sewers and paved roads
- Fixed bug where barbarian large and epic walls weren’t displaying on battle map correctly (still referred to as wall in game)

- Add general recruitment to Proconsuls palace / fourth level city.

- Enabled recruitable generals / warlords in the imperial palace / level five city.
- Enabled barbarian factions to build large and epic stone walls.

Barbarian Invasion buildings now display on the settlement battle map

Added large and huge city models from BI for barbarian factions. This is not reflected on the battle map… yet.

- Bugfix: barbarian stone walls not displaying correclty on campaign map
- Add missing building descriptions
- Add additional buildings to barbarian factions from Barbarian Invasion
- add highways to ALL factions (Eastern factions recieve Royal Roads)
- Add fourth level temple to barbarian factions
- Move temple units to appropriate military buildings

- Add Army Barracks
- Move barbarian shrine units to Army Barracks
- Add foundry
- Fix missing range for Britons