Make some comment tweaks and additions, plus a small logic change for strict (if negligible) memory savings.
Make some comment tweaks and additions, plus a small logic change for
strict (if negligible) memory savings.

* subversion/mod_dav_svn/reports/update.c
  (update_ctx_t, item_baton_t): Comment tweaks.
  (upd_change_xxx_prop): Comment tweaks mostly, but also, only cache
    removed_props in the one case we'll actually use them -- for copied
    directories and files.

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