[airstrike] Recent changes.

[Ulf Ekström]

> There's also a problem that the "new-defaults" file seems to be missing.
> Could you add it to CVS and/or the media-package?
> 
> Copying the old "defaults" to new one resulted in error messages and
> segfault.  I guess you've changed the syntax a bit... :-)

I have checked in a new "defaults" file (and changed the code to use it).

A little more on the new format. It is a (stupid) line based format.
With stupid I mean
that almost all parsing etc is moved into the functions that implement
different shell commands.

Example:

In the new level format file you can do

sprite zeppelin 100 100

to create a zeppelin at (100,100). However you might want to do more
things with it after that. So I have added "tags" to sprites. You can
give them name by which you can reference them, like so:

sprite zeppelin 100 100 nameofsprite
ai player1 nameofsprite

This first creates the sprite and gives it the tag "nameofsprite".
Then we set the
ai of this sprite to the player1 "ai". (Maybe ai is a stupid name..)

Have a look in level.c if you wonder how these commands are
implemented. It should
be very easy to understand I hope.

Ulf