walterroach aa7825d4aa Reproducible unit naming
Splits infantry and other unit IDs.

Resets IDs to start from zero at each press of "Takeoff"

Direct access to the the `Game` class IDs is done on the `Operation` class to
preserve save compat
2020-12-28 09:27:33 -06:00
..
2020-12-28 09:27:33 -06:00