kohabug 2380 Correcting serialitems table structure and fixing duplicate barcode...

kohabug 2380 Correcting serialitems table structure and fixing duplicate barcode check

The current serialitems table structure does not provide for a *:1 relationship with
the serial table. This causes a problem when attempting to add multiple items to a given
serial. The db throws an error when attempting to INSERT in  serialitems due to serialid.serialitems
being a unique key. A further side effect is that the marc record is updated with the
item inspite of the error. The mods to the serialitems table structure in this patch
drop serialid.serialitems as a key and make itemnumber.serialitems the primary key
creating a *:1 relationship with the serial table. This patch also makes serialid.serialitems
a foreign key referencing serialid.serial to maintain referential integrity.

Fix for duplicate barcode check

Signed-off-by: Galen Charlton <galen.charlton@liblime.com>
Signed-off-by: Joshua Ferraro <jmf@liblime.com>