This allows unique identification across saves. The front-end needs to
be able to differentiate the first carrier in game A and the first
carrier in game B, but because carriers (and other non-airfield CPs) are
assigned IDs sequentially, collisions were to be expected. The front-end
can't tell the difference between a reloaded game and a new turn, so we
need to ensure different IDs across games.
This is a handy cleanup anyway, since callers constructing CPs no longer
need to manually track the CP ID counter.
Fixes https://github.com/dcs-liberation/dcs_liberation/issues/2078.
This may not be the way to do this long term, but it is how the old map
works so it's at least not a regression. It might be better to generate
events for the between-turn changes in state instead.
https://github.com/dcs-liberation/dcs_liberation/issues/2039
There are some TODOs here but th behavior is flagged off by default. The
biggest TODO here is that the time spent frozen is not simulated, so
flights that are engaged by SAMs will unfreeze, move slightly, then re-
freeze.
https://github.com/dcs-liberation/dcs_liberation/issues/1680
