ra_serf: Simplify propfind report parsing and be smarter with pools.
ra_serf: Simplify propfind report parsing and be smarter with pools.

* subversion/libsvn_ra_serf/property.c
  (prop_state_e): Add states that we can be in for a PROPFIND.
  (prop_info_t): Structure to hold the currently parsed property.
  (svn_ra_serf__propfind_context_t): Remove in_prop, in_response, collect_cdata
  flags (moved to prop_state_e); remove ns, attr_name, attr_val, attr_val_len,
  attr_encoding (moved to prop_info_t).
  (push_state): New function to control our XML state.
  (start_propfind, end_propfind, cdata_propfind): Rewrite to use common state
  code and keep an eye on our pool usage by using temporary pools.
  (svn_ra_serf__deliver_props): Ensure our property elements are in the same
  pool as the hash we are putting them into.

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