CCBC-473: Add cbc to index for manpages

This allows the main page to provide a link to the cbc utility

Change-Id: Id80471436a6e63539f906b36f070273437e37935
Reviewed-on: http://review.couchbase.org/39180
Tested-by: Mark Nunberg <mnunberg@haskalah.org>
Reviewed-by: Brett Lawson <brett19@gmail.com>