CBIDXT-83 Integration Changes (Latest Key Format)

Change the keys to 2-dimensional array to avoid any future
incompatible change. The first integration will only work with
non-composite keys

Change-Id: I562a0cbe04d56fb914e1761b6b19201c8b4480a3
Reviewed-on: http://review.couchbase.org/38655
Reviewed-by: John Liang <johliang00@gmail.com>
Reviewed-by: Deepkaran Salooja <deepkaran.couchbase@gmail.com>
Tested-by: Deepkaran Salooja <deepkaran.couchbase@gmail.com>