JSCBC-268: Correct issue with durability polling behaving incorrectly.
JSCBC-268: Correct issue with durability polling behaving incorrectly.

When a durability requirement that was not possible with the current
cluster configuration was passed, the client was not erroring and instead
was capping the durability requirement to the cluster configuration.

Change-Id: I005409edf0d11f6b3fe741190d60ee9dc7899dc6
Reviewed-on: http://review.couchbase.org/57687
Well-Formed: buildbot <80754af91bfb6d1073585b046fe0a474ce868509@couchbase.com>
Reviewed-by: Mark Nunberg <dab05a0fe859c5cb93882b2a75a0d613501b07be@couchbase.com>
Tested-by: Brett Lawson <c8c4369773d7d7226e031f0c4af62e3f38a08510@gmail.com>

couchbase/couchnode,brett19/couchnode,brett19/couchnode,couchbase/couchnode,brett19/couchnode,corbinu/couchnode,couchbase/couchnode,corbinu/couchnode,corbinu/couchnode,couchbase/couchnode