These two fields are just for information purposes, as Numerus does not
have any way to wire transfer using these, but people might want to keep
these in the contact’s info as a convenience.
Since not every contact should have an IBAN, e.g., customers, and inside
SEPA (European Union and some more countries) the BIC is not required,
they are in two different relations in order to be optional without
using NULL.
For the IBAN i found an already made PostgreSQL module, but for BIC i
had to write a regular expression based on the information i gathered
from Wikipedia, because the ISO standard is not free.
These two parameters for the add_contact and edit_contact functions are
TEXT because i realized that these functions are intended to be used
from the web application, that only deals with texts, so the
ValueOrNil() function was unnecessarily complex and PostreSQL’s
functions were better suited to “convert” from TEXT to IBAN or BIC.
The same is true for EMAIL and URI domains, so i changed their parameter
types to TEXT too.
Closes#54.
