- re-enabled the vanilla Estate building

Updated to patch 6.2

Updated to match version 2.1.0 changes from the main mod

- tech tree has been reverted to vanilla so no more issues with tech keys not working correctly when it comes to effects etc

- Nehekharan Citadel is once again available

- should have fixed an issue where certain technologies were not correctly increasing unit capacity

- fixed several instances of PLACEHOLDER texts appearing on buildings

- re-enabled the Public Order, Income and Growth buildings from vanilla - still need to tweak what units are made available
- updated the Ushabti building chain so it now recruits Arkhan's unit variants

I still need to see how want to implement the Bone Giant. As far as I can see, Arkhan doesn't have access to this in TK:E. I'll also take a look at re-adding the Terrorgheist and Black Coach.

- fixed an issue where scrap upgrades were locked out for The Followers of Nagash

Updated for patch 6.0

Updated for patch 5.3