[airstrike] Recent Airstrike changes

[Ulf Ekström]

> You will also need the attached patch for a couple of other 
bugs.  I didn't 
> commit them, because I'm not sure whether they are the correct 
way of
> handling the object core stuff.  Ulf mailed that he will back 
next tuesday
> and will then look more into the bugs.

The fixes look fine. I forgot that we were assuming calloc'd
memory for some of the stuff. Please apply.

Ulf (from an iMac in Göttingen, I will look at getting the 
game running tomorrow).