This PR:
- Introduces a new member of UnitType, hit_points, which is an abstract
representation of the durability of a unit, and loads it in from the
YAML files in the various subclasses (Ship, Ground etc).
- Adds scripts for populating/updating the unit YAML files with hit
point data from DCS. This script also gets the data for static objects,
but I'll leave the plugging in of static object data into Liberation for
another PR.
- Updates the unit YAML files by running the above scripts.
I did toy with the idea of adding this data to the unit definitions in
pydcs via an export from DCS, but it would be a more involved change,
since the current pydcs export script runs in the Hooks Lua environment
in DCS and AFAICT the hit points (via Unit.getLife()) is run in the
mission scripting environment.
