MB-100: capture all bucket's ddocs in cbcollect_info

Change-Id: I4fb3b1652f85d0d2301e91514de3855adb4ceb88
Reviewed-on: http://review.couchbase.org/25713
Reviewed-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>
Tested-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>