LP#1145213: improvements to record merge

LP#1145213: improvements to record merge

This patch checks for suffix and prefix of call number before merging
assets and ensures that unused call number records are marked
deleted.

To test:

[0] Apply the patch.
[1] Attempt a record merge where each record has a volumes with the
    same call number label and owning library but different
    affixes. Verify that the volumes and their associated copies
    are not merged onto the same volume..
[2] Attempt a merge with records having matching volumes. Verify
    that the copies are moved to one volume and that the other is
    marked deleted.

Signed-off-by: Rogan Hamby <rhamby@equinoxinitiative.org>
Signed-off-by: Cesar Velez <cesar.velez@equinoxinitiative.org>
Signed-off-by: Galen Charlton <gmc@equinoxinitiative.org>