Bug 7688: (follow-up) set firstacquidate in updatedatabase if it's not set

Bug 7688: (follow-up) set firstacquidate in updatedatabase if it's not set

firstacquidate is now a mandatory field, so it must be set.

The updatedatabase process set firstacquidate value to one of:
- the planned date of the first serial for this subscription, or if not
  found,
- the subscription start date.

+ auto-select the numbering pattern when modifying a subscription.

Signed-off-by: Bernardo Gonzalez Kriegel <bgkriegel@gmail.com>
Signed-off-by: Galen Charlton <gmc@esilibrary.com>