Make some FK constraints on config.metabib_field.id deferrable

Signed-off-by: Dan Wells <dbw2@calvin.edu>
Signed-off-by: Lebbeous Fogle-Weekley <lebbeous@esilibrary.com>
Upgrade script for config.metabib_field sequence redo

[LFW: s/DROP FUNCTION/DROP FUNCTION IF EXISTS/]

Signed-off-by: Dan Wells <dbw2@calvin.edu>
Signed-off-by: Lebbeous Fogle-Weekley <lebbeous@esilibrary.com>
Stamping 0841: make space in config.metabib_field sequence

Signed-off-by: Dan Wells <dbw2@calvin.edu>