LP#1312945: auth-auth linking: cache less agressively and look for all links

There was a logic inversion that was causing miss-use of a per-
record cache mechanism.  I remove that entirely, as it's not helpful
in practice.

Also, after finding one use of a linked field we moved on to the
next, though it is possible for more than one link to exist for
different uses of a name, say.  Now we'll loop through all fields
to find all possible linkages.

Signed-off-by: Mike Rylander <mrylander@gmail.com>
Signed-off-by: Srey Seng <sreyseng@gmail.com>
Signed-off-by: Galen Charlton <gmc@esilibrary.com>
LP#1312945: authority.calculate_authority_linking and multiple linked tags

The function "authority.calculate_authority_linking" was not able to deal with
situations where there are multiple marc tags that are linkable. The function
only process the first tag that contains a linking_subfield and returns that
to be inserted into the authority_linking table, even when there are more than
one of the same tag with linking_subfield.

Added an additional loop to loop through each tag, for situations where there are
multiples of each tag.

Signed-off-by: Srey Seng <sreyseng@gmail.com>
Signed-off-by: Mike Rylander <mrylander@gmail.com>
Signed-off-by: Galen Charlton <gmc@esilibrary.com>
LP#1312945: baseline schema update

Signed-off-by: Mike Rylander <mrylander@gmail.com>
Signed-off-by: Srey Seng <sreyseng@gmail.com>
Signed-off-by: Galen Charlton <gmc@esilibrary.com>
LP#1312945: add regression test

This adds a test for the change to the
authority.calculate_authority_linking stored function.

Signed-off-by: Galen Charlton <gmc@esilibrary.com>
LP#1312945: pin schema update

Signed-off-by: Galen Charlton <gmc@esilibrary.com>