Small reform script fix.

Fixed wrong reform requirements carried over from test build.

Fixed two minor UI issues:
- DeI italic bodyguard units being recruitable
- unavailable units being visible but greyed out in the recruitment tab

Went all the way now and created a new separate unit for the Equites Optimi so the other italic factions keep their separate unit.

Fixed wrong unit name for Equites Optimi.

Fixed a unit description.

Streamlined unit descriptions some more.

Updated unit descriptions.