Strong Walls to Iron Dome 1.23

Version 1.23: Removed 'grantfortification' from city, which was preventing all unit types from being able to skip turn.

Version 1.22: Improve compatibility with other mods.

Version 1.21: Fixing what I regretfully broke. Units are again granted to all players, and not only AI.

Version 1.2: Reduce global unit maintenance cost for select units. Revise SQL structure for Iron Dome.

Version 1.1: Reduce maintenance cost of all granted units -2 gold.

Version 1.0: Final release. Grants free Anti-Air unit upon researching Ballistics, and a free Fighter plane after Flight.