dynamic width for document title

looks more pretty with short title of document

Change-Id: I9c57ac391d8183814e8f7328c6cd63d5c414b33a
Reviewed-on: http://review.couchbase.org/36018
Reviewed-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>
Tested-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>