NCBC-562: Provide configurable wait timeout for operations in mid-fight

Change-Id: Ib61e91cb29122b941032684cb9d1c5fbe8cd3d57
Reviewed-on: http://review.couchbase.org/40841
Reviewed-by: Jeffry Morris <jeffrymorris@gmail.com>
Tested-by: Jeffry Morris <jeffrymorris@gmail.com>