Don't use automatic supply to avoid starvation at the update

Food supply during update adds complexity to the update.  How much
good it does to players is highly doubtful; certainly nobody can rely
on it.  It isn't covered by the starvation command.  Starving ships or
land units can steal enough food from their sector to make it starve,
too.  Finally, the supply code is notoriously hard to use correctly.
We don't know of issues with the update's use, but we haven't
convinced ourselves that there aren't any either.

info/supply.t

@@ -26,15 +26,11 @@ A unit that fights may use a basic load of supplies
 to attack with.  (depending on the intensity of combat. The more intense the
 combat, the more chance the unit will use a basic load of supplies)
 .s1
-During the update, each unit will attempt to draw food supplies just before
-starvation is calculated.
-.s1
 When a unit needs to draw supplies, such as when you use the supply command,
 or the unit wishes to attack, or is attacked, etc, it must attempt to get
 them from supply sources. Other things may use the same routines, such as
-loyal sectors, which will draw food from supply sources when in danger of
-starvation, and ships/forts/sectors, which will draw shells when they need
-them to fire defensively.
+ships/forts/sectors, which will draw shells when they need them to
+fire defensively.
 .s1
 .L "Supply Sources"
 .s1
@@ -89,7 +85,4 @@ OTHER USES OF SUPPLY
 In general, when any land unit/ship/fort needs shells, it will attempt to
 draw them before use, if it does not already have them.
 .s1
-Also, units/ships/sectors will use supply sources to get enough food during
-the update so that they do not starve.
-.s1
 .SA "lload, LandUnits"