SERVER-9647 don't transform 2dsphere desc fields into asc
SERVER-9647 fix test for small_oplog
SERVER-9694 fix test to cover all GLE stepdown cases
SERVER-9502 prohibit _id as RegEx

Otherwise, this breaks when replication attempts to do a query with the regular expression as _id.
SERVER-9502 fix assert code
SERVER-9502 fix assert code in unit test