FIXES:
- Just a minor one, broke the Wonder Civilopedia entries in my last update so fixed them and updated them a little whilst I was there - no gameplay changes.
- How are there still typos!?

CHANGES
- Only recently discovered that invisible units cannot capture cities. When the city is down to 0 defence, they can enter the city and will eliminate any garrisoned units but the city won't change ownership. This is due to code that cannot be changed so I've decided to make it a feature by updating the Trojan Horse and SAS unit and promotion civilopedia entries to note this.
- The USS Akron can now fly over water tiles without needing to embark. In order to make this, the unit belongs to a new 'Airship' unit class so it no longer benefits from naval bonuses but can earn the same promotions as Carriers. It no longer has combat animations either but since it can't attack, I don't feel it's a big deal.
- Minor text amendments.

- Coded additional failsafes to prevent the unique units from appearing outside of building the wonders.
- The USS Akron can now carry 3 aircraft instead of 2 - this links with the lore of the unit and although it can earn extra cargo space from promotions, since it doesn't benefit from barracks etc and can't attack, it's hard to do so and therefore a little buff seems in order.
- The Winans Steam Gun now appears as one tank instead of two - wanted this originally but coded the art incorrectly, purely cosmetic.
- Fixed a few coding errors around how AI civs use the units though probably nothing noticable.

- Fixed code error where invisible units could still be seen by enemies
- Rebalanced Trojan Horse, bonus when attacking cities reduced from 250% to 200% but bonus when stacked with a Great General increased from 15% to 30%, wanted to focus on the hiding unit aspect of the unit
- Renamed and combined the 300 Spartan promotions, just efficiency, no game play changes
- Fixed Civilopedia text errors