ra_serf: Improve pool usage within the update report.
ra_serf: Improve pool usage within the update report.

* subversion/libsvn_ra_serf/update.c
  (report_dir_t, report_info_t): Add in pool field associated with directory
  and file; Store base_rev field with the dir and delta_base URL with file.
  (push_state): Create independent pool for root, dirs, and files. (may want
  to delay the pool creation even further); split the props to be dir-based
  instead of global.
  (open_dir): Lazily open dir_batons so we don't exhaust fds.
  (close_dir): Move from later in file; ensure our baton was opened; clear
  dir's pool when we close it; don't take an explicit pool - we'll use the dir
  pool instead.
  (handle_fetch): Open dir and file batons when we get our file response;
  use appropriate pools.
  (delta_file, fetch_file): Init prop_ctx to NULL; delay opening baton; use
  appropriate pools.
  (start_report): Store our base_rev; don't open batons here; use appropriate
  pools.
  (finish_report): Don't pass a pool; remove items from the pending_dir_close
  list.


git-svn-id: f8a4e5e023278da1e04e203c7fe051e3c4285d88@858475 13f79535-47bb-0310-9956-ffa450edef68

YueLinHo/Subversion,wbond/subversion,YueLinHo/Subversion,wbond/subversion,wbond/subversion,wbond/subversion,YueLinHo/Subversion,YueLinHo/Subversion,wbond/subversion,YueLinHo/Subversion,wbond/subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,wbond/subversion