[slashem] Weight calculation bug

[Janis Papanagnou]

A scenery at the Castle; soldiers of different grades throw frag
grenades at me, I kill them and their bodies with their remains
are piled up. One heap that I inspected more closely had a couple
stacks of frag grenades as shown in the left column (with their
weight displayed in braces)

a - 14 frag grenades {400} a - 13 frag grenades {325}
f - 11 frag grenades {525} f - 10 frag grenades {250}
j - 2 frag grenades {175} j - a frag grenade {25}

These weights are not not correct, though. A single frag grenade has
a weight of {25}. If I pick up one item from any of the three stacks
that value gets corrected. And after having picked up an item from
each stack all values are okay (as depicted in the right column).

If I pick up a stack of miscalculated frag grenades (I tested that
with 3 frag grenades {100}) my inventory weight gets also incremented
by that wrong value (and dropping these will correct my inventory
weight but not the weight of the dropped grenades).

Janis