Copy summary group by call number, add max_lines

Copy summary group by call number, add max_lines

Group copy summary by call number in addition to circ lib and
copy location.

Also, support setting of max_lines for limiting the number
of call numbers output -- useful for bibs with lots of volumes
at a single library -- to prevent the search results page from
growing too long.

Signed-off-by: Jeff Godin <jgodin@tadl.org>