Bug 23644

It would be a timesaver to have guarantee accounts automatically update when a guarantor account is updated.  

We are thinking the following would be good parameters for this:
* When a guarantor or guarantee account is updated, have Koha check for connected accounts.
* If detected, a checkbox is added to the edit screen to "Update connected accounts"
* Upon saving the record, if the checkbox is checked, Koha will present an edit screen for each of the connected accounts, with the fields pre-populated with the updated information from the original edit screen.  Staff can then choose to save the record as is, or modify each field as necessary (for instance, if each person had their own unique email address)

Basically, we want to have Koha do the heavy lifting of updating multiple guarantee accounts at once instead of doing it ourselves.