Fix bug made more visible by r13973.  If a hook script put jobs in the background, the svn operation would block waiting for the background processes to finish even if the hook script itself had exited.
Fix bug made more visible by r13973.  If a hook script put jobs in the
background, the svn operation would block waiting for the background
processes to finish even if the hook script itself had exited.

Found by: loren jan wilson <loren@solar.uchicago.edu>

Review by: maxb
           rooneg
           philip
           ghudson

* subversion/libsvn_repos/hooks.c (run_hook_cmd): Make the read and write
  ends of the stderr pipe non-inherited by child processes.

jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion