Cap squadron size, limit replenishment rate.

This caps squadrons to 12 pilots and limits their replenishment rate to
1 pilot per turn. Should probably make those values configurable, but
they aren't currently.

Fixes https://github.com/dcs-liberation/dcs_liberation/issues/1136

qt_ui/windows/AirWingDialog.py

@@ -48,10 +48,10 @@ class SquadronDelegate(TwoColumnRowDelegate):
             return self.squadron(index).nickname or ""
         elif (row, column) == (1, 1):
             squadron = self.squadron(index)
-            alive = squadron.number_of_living_pilots
             active = len(squadron.active_pilots)
             available = len(squadron.available_pilots)
-            return f"{alive} pilots, {active} active, {available} unassigned"
+            on_leave = len(squadron.pilots_on_leave)
+            return f"{active} active, {available} unassigned, {on_leave} on leave"
         return ""