LP1883171 & LP1940663: Modify do_checkin for asset.copy_inventory

LP1883171 & LP1940663: Modify do_checkin for asset.copy_inventory

Modify the do_chekin method of Circulate.pm to create a new
asset::copy_inventory object when the do inventory modifier is used.

This change necessitates moving the check for a floating copy up to
where the do inventory code is run and subsequent modifications to the
transit and noop checkin code.

This work was sponsored by NOBLE.

Signed-off-by: Jason Stephenson <jason@sigio.com>
Signed-off-by: Michele Morgan <mmorgan@noblenet.org>