This should have been done much earlier, but wasn't done for nostalgic reasons.
To new users, it didn't make sense that you could just enter an amount, and
revbank would just accept that as "withdrawal or unlisted product". It existed
for backwards compatibility with the very first revbank version, which didn't
have a product list, and which was not yet used with a barcode scanner. You
would simply enter the amount and your name, and there were no further
statistics.
Nowadays, there are statistics that are messed up if you don't use the product
codes. And some people were looking for a withdrawal command, and try 'take' as
that seems closest to it, but which instead transfers money to another account.
Additionally, some texts were changed for improved clarity. ("Enter username to
pay", when withdrawing, was confusing: one expects money back, not to pay more.)
The signatures feature has been "experimental" since Perl 5.20 (May 2014), but
expected to stay. After 8 years I'm ready to take the risk :)
Have added Perl v5.28 (June 2018) as the minimum requirement, even though the
current revbank should work with 5.20, to see if this bothers any users. Perl
v5.28 is in Debian "buster", which is now oldstable.
