Add autoFlush flag to Schema

The flag controls whether or not writes are sent immediately to
the database.  By delaying writes larger units can get sent in a
single request.  Right now we only plan to make use of the flush
hint on NoSQL based systems.

Change-Id: I79b2a1aec822e1c4b6abf5c6788429ab7becce1d
Signed-off-by: Shawn O. Pearce <sop@google.com>
4 files changed