Updated task-server code

[Niels Möller]

I've updated my old task-server code. Interesting changes:

* It can be started by my patched wortel (patch included in the
  archive).

* It gives out local reference counted id:s to users, as Marcus
  suggested when we discussed it months ago. (One of the things that
  made me believe global id:s were more natural is that the task
  server needs an efficient way to map global task id:s to tasks, in
  order to find out which task each client thread belongs to. That
  table is still there, despite the local id:s).

* It still uses only static memory allocation, which I think is a
  feature at this point in time, but I think the new code is easier to
  adapt to dynamic allocation.

One ugly aspect of the code is that error codes are chosen quite
arbitrarily from errno.h. I don't know what's the right place to
define more relevant error codes.

Anyway, the code is available at
http://www.lysator.liu.se/~nisse/misc/task-0.0.tar.gz.

Numbers: about 1500 lines of C, stripped binary about 13K, and a fairly
large bss segment with space for some 1024 tasks.

Happy hacking,
/Niels