ra_serf: Improve "Could not lookup hostname" error message.
ra_serf: Improve "Could not lookup hostname" error message.

subversion/libsvn_ra_serf/serf.c
  (svn_ra_serf__open): Use svn_error_wrap_apr() to produce detailed error
  message.

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