Add proper cancel handling in the restore phase of 'svn up'.
(Bumped into this while reading through recent changes.)

* subversion/libsvn_wc/adm_crawler.c
  (restore_file): Add cancel_func support.

  (svn_wc_restore): Document TODO. Update caller.

  (restore_node): Pass cancel_func.
  (report_revisions_and_depths,
   svn_wc_crawl_revisions5): Update caller.


git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1618862 13f79535-47bb-0310-9956-ffa450edef68