Following up on r1555774, remove the old pause handling from the legacy serf
xml parser and fix an unlikely corner case in the EOF handling.

* subversion/libsvn_ra_serf/ra_serf.h
  (svn_ra_serf__xml_parser_t): Remove pending/pause variables.
  (svn_ra_serf__process_pending): Remove function.

* subversion/libsvn_ra_serf/update.c
  (update_delay_baton_t): Remove unused variable. Add boolean.
  (update_delay_handler): Store if we have a network eof.
  (process_pending): Don't handle spillbuf eofs if the network is not at eof.

* subversion/libsvn_ra_serf/util.c
  (SPILL_SIZE): Remove unused macro.
  (svn_ra_serf__pending_t): Remove unused struct.
  (HAS_PENDING_DATA): Remove unused macro.
  (write_to_pending): Remove function.
  (inject_to_parser): Remove function, fold into caller.
  (PENDING_TO_PARSE): Remove macro.
  (svn_ra_serf__process_pending): Remove function.
  (svn_ra_serf__handle_xml_parser): Remove pending/pause handling.


git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1555798 13f79535-47bb-0310-9956-ffa450edef68