Teach the BDB implementation of svn_fs_node_origin_rev() to use an index table to do its thang.
Teach the BDB implementation of svn_fs_node_origin_rev() to use an
index table to do its thang.

* subversion/libsvn_fs_base/tree.c
  (struct get_set_node_origin_args, txn_body_get_node_origin,
   txn_body_set_node_origin): New.
  (base_node_origin_rev): Use the new `node-origins' table as a
    persistent cache of information vital to answering the "what was
    the original revision" question.

git-svn-id: f8a4e5e023278da1e04e203c7fe051e3c4285d88@867820 13f79535-47bb-0310-9956-ffa450edef68

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