Permit NoSQL results to be out-of-order

Just like with a SQL database, a NoSQL system might be able to return
results out of order more efficiently than in-order when there is
no explicit ORDER BY clause in the query.  Support that by passing
through a hint indicating if the order needs to be preserved, or not.

Change-Id: Ic601fd3277936e599b590c508e2435bc5bf5f95b
Signed-off-by: Shawn O. Pearce <sop@google.com>
6 files changed