NCBC-692: Increase field sizes to avoid overflow errors

Change-Id: Ieb4eeb20e8c6ab9e246f831884d5576d2aacf2ea
Reviewed-on: http://review.couchbase.org/42376
Reviewed-by: Simon Baslé <simon@couchbase.com>
Reviewed-by: Jeffry Morris <jeffrymorris@gmail.com>
Tested-by: Jeffry Morris <jeffrymorris@gmail.com>