[project @ 2003-06-05 12:09:52 by panne]

Attention: Tentative fix only! But at least this works much better
than before.

From the Linux man page for waitpid:

   [...]
   ERRORS
          ECHILD if  the  process specified in pid does not exist or
                 is not a child of the calling process.   (This  can
                 happen  for  one's  own  child  if  the  action for
                 SIGCHLD is set to SIG_IGN. See also the LINUX NOTES
                 section about threads.)
   [...]

Consequently, we don't ignore SIGCHLD anymore. Further changes:

   * SIGCONT is not ignored anymore, either. What was this for?

   * Don't use WUNTRACED in waitpid. Again, what was this for?