r25690: - only use a readonly traverse in ldb_search when not in a transaction. When...

r25690: - only use a readonly traverse in ldb_search when not in a transaction. When we are in a transaction then we could be in a top level modify operation (such as rename), so we must use a writeable traverse so that the async callbacks can do the modifies while the search is progressing.

- don't do the lockall operation on the tdb during a ldb search if in
  a transaction, as this would prevent modifies by callbacks as well
(This used to be commit aa9ab431e071882f42ebc882e809ae1d4b8778d4)