Make ASAP a checkbox and maintain ASAP on changes.

Fixes https://github.com/Khopa/dcs_liberation/issues/642

gen/ato.py

@@ -20,6 +20,7 @@ from game.theater.missiontarget import MissionTarget
 from game.utils import Speed
 from .flights.flight import Flight, FlightType
 from .flights.flightplan import FormationFlightPlan
+from .flights.traveltime import TotEstimator
 
 
 @dataclass(frozen=True)
@@ -54,6 +55,11 @@ class Package:
 
     delay: int = field(default=0)
 
+    #: True if the package ToT should be reset to ASAP whenever the player makes
+    #: a change. This is really a UI property rather than a game property, but
+    #: we want it to persist in the save.
+    auto_asap: bool = field(default=False)
+
     #: Desired TOT as an offset from mission start.
     time_over_target: timedelta = field(default=timedelta())
 
@@ -127,6 +133,9 @@ class Package:
             return max(times)
         return None
 
+    def set_tot_asap(self) -> None:
+        self.time_over_target = TotEstimator(self).earliest_tot()
+
     def add_flight(self, flight: Flight) -> None:
         """Adds a flight to the package."""
         self.flights.append(flight)