Updated to libcouchbase-2.3.0.

Change-Id: I2ccc7b72b619f7c03da939a8ee99719c374eef31
Reviewed-on: http://review.couchbase.org/34148
Tested-by: Brett Lawson <brett19@gmail.com>
Reviewed-by: Mark Nunberg <mnunberg@haskalah.org>