Following up on r1552043, handle http status 404 as an http failure. Use the
new non-fatal handle mode (see r1551993) in the few places where a 404 error
is not a failure.

Remove duplicated http status based error messages from the error chains.

* subversion/libsvn_ra_serf/blame.c
  (svn_ra_serf__get_file_revs): Avoid duplicated errors.

* subversion/libsvn_ra_serf/commit.c
  (open_root): Use standard error when possible.

* subversion/libsvn_ra_serf/getdate.c
  (svn_ra_serf__get_dated_revision): Avoid duplicated errors.

* subversion/libsvn_ra_serf/getlocations.c
  (svn_ra_serf__get_locations): Avoid duplicated errors.

* subversion/libsvn_ra_serf/getlocationsegments.c
  (svn_ra_serf__get_location_segments): Avoid duplicated errors.

* subversion/libsvn_ra_serf/get_lock.c
  (svn_ra_serf__get_lock): Avoid duplicated errors.

* subversion/libsvn_ra_serf/inherited_props.c
  (svn_ra_serf__get_inherited_props): Avoid duplicated errors.

* subversion/libsvn_ra_serf/log.c
  (svn_ra_serf__get_log): Avoid duplicated errors.

* subversion/libsvn_ra_serf/mergeinfo.c
  (svn_ra_serf__get_mergeinfo): Avoid duplicated errors.

* subversion/libsvn_ra_serf/options.c
  (svn_ra_serf__exchange_capabilities): Avoid duplicated errors.

* subversion/libsvn_ra_serf/property.c
  (svn_ra_serf__wait_for_props): Avoid duplicated errors.

* subversion/libsvn_ra_serf/replay.c
  (svn_ra_serf__replay): Avoid duplicated errors.

* subversion/libsvn_ra_serf/update.c
  (finish_report): Avoid duplicated errors.


git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1552054 13f79535-47bb-0310-9956-ffa450edef68