Credit card blacklist

Any card on the list is just treated as though it is not present, preventing it
from being used.

Declines should be an Int

Previously this retured a string and everywhere that used it had to
convert it into an it, or handle it if it's nil.

That's dumb.
Now it's always an int, and `nil.to_i` is 0 anyway so I don't have to
check that either.

Order Transactions by Date

In my testing the natural order just happened to be the date order
because I had so little data.

But in the real world we should probably be more explicit!

Transaction Note Can Be Null

Not only is it allowed, but actually there's a ton of empty notes. Every
monthly account activation is missing a note, so practically every user
that has transactions will have empty notes.

Merge branch 'tx-list'

* tx-list:
  Admin Command Menu + Admin Financial View
  Transactions List
  Customer Financials
  Telephone Link

Customer Financials

I've pulled out information about payment methods and bitcoin into its
own thing. It's kind of a repository, except that it only exposes
fetchers and doesn't load anything generally.

There's also a few new methods here that aren't used yet, but will be
shortly.