Fix a race in ra-test that could cause a deadlock in BDB cleanup.
Fix a race in ra-test that could cause a deadlock in BDB cleanup.

* subversion/tests/libsvn_ra/ra-test.c
  (close_baton_t): Remember the handle of the child svnserver process.
  (open_tunnel): Set subprocess state o APR_KILL_NEVER, regardless of
   platform, so that pool cleanup cannot interact with normal
   subprocess termination. Remember the process handle in the
   close-tunnel baton.
  (close_tunnel): Kill the child svnserve process.


git-svn-id: f8a4e5e023278da1e04e203c7fe051e3c4285d88@1659010 13f79535-47bb-0310-9956-ffa450edef68

YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion