Continued work on the XML parser pausing and processing. In particular, this revision enables reading from the "spill" file, and injects that content into the XML parser.
Continued work on the XML parser pausing and processing. In particular,
this revision enables reading from the "spill" file, and injects that
content into the XML parser.

* subversion/libsvn_ra_serf/util.c:
  (get_buffer): new function to return an allocated buffer, or to recycle
    a previous buffer from the parser context.
  (return_buffer): returns a buffer back to the parser context.
  (write_to_pending): use the new get_buffer() helper
  (svn_ra_serf__process_pending): expand commentary. use the new
    get_buffer() and return_buffer() helpers. add processing of the spill
    file.

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