LMDB 0144da6eab00cf5f321d5c6794175485ba3efefd

Fix crash caused by iterating existing cursor following a delete.

Author: Howard Chu <hyc@symas.com>
Date:   Sat Sep 21 14:37:11 2013 -0700

    ITS#7701 fix mdb_rebalance

    Must copy tmp cursor back to real cursor when merging into tmp cursor.
LMDB 912e09fd04e0512e6f764176a4a0a2ab009c87d1

Author: Howard Chu <hyc@symas.com>
Date:   Sun Sep 15 13:08:29 2013 -0700

    ITS#7681 fix 18a07eb7c2dc33372455a6040984cd6b699b41a5

    Set rc=0 when taking the SET_RANGE branch