SERVER-10464 allow mongodump to dump oplog without a query containing a ts field
(cherry picked from commit 50045df21469d45216c5fb8899d68818fcc7f38a)
SERVER-13603 Move option testing support code into shared test helper
(cherry picked from commit f7d78f9511d3e4fa156d6f94322f5a690a21bc20)
Merge remote-tracking branch 'upstream/v2.6' into v2.6