[crossfire] Tweaking alchemy

[Nicolas Weeger]

>  One thing that I also thought would be needed is to add some slow decay
> factor to most all flesh items like there are for a few special ones
> (demon ichor). You shouldn't be able to carry around the orc corpse for
> 3 months and expect it to still be edible.
> 
>  That wouldn't be hard to do, but once again, it gets into the merging
> issue.

What about something more simpler, even if less realistic: every tick,
one food has a 0.01% (or anoyher number) chance of rotting (if nrof > 1
only one rots)?
No mergin issue, will decrease available food, introduces some random
element, pretty easy to do.

Ryo