Renamed methods to show they are for ARB subscriptions.

We're going to rename our Payment to Subscription, which may get
confusing. It'll be less confusing if we consistently use the phrase
"ARB Subscription" when talking about the subscription model from
Authorize.Net.
Installed better_errors gem for easier debugging.
Refactor: Extracted admin organization menu partial.

We're about to add a fourth tab. It seemed like time.
Text fix: Removed redundant data loader.
Fixed ARB subscription builder specs.

We renamed some methods and never reran the tests that tested them.
Weird.
Renamed Payment to Subscription.

We didn't rename the database table, because we're developing on
multiple branches and we don't want to have to keep migrating backwards
and forwards.
Installed simple_form.
Made simple_form forms look more like other forms.

Other forms in the app put paragraph tags around their inputs;
simple_form uses .input for the same purpose, so we apply the
same margins there.
Fixed debatable syntax error in admin users page.

RubyMine complains, Ruby seems okay with it, but it's clearer with
white space.
Payment history: new payment action.

Changed `menu_item` helper to use the active class if we're on
the target URL or anywhere beneath it in the URL tree.
Added strong_parameters gem.

For use in `PaymentsController`, and also general movement toward Rails
4.
Payment history: create action.
Payment history: index action.
Set default time zone to Eastern.

Really? We've been using UTC all this time?

Fixed bug where todo reminders should be sent for items due in two days,
but actually were only sent for today and tomorrow (and very early the
next day).
Payment history: Default paid date to time of entry.

https://www.pivotaltracker.com/story/show/67956896
Payment history: edit/update actions.

Also made it possible to set date and time from the form. (Previously we
only had a default value.)

We removed seconds from our time formats, on the theory that no one
will want to enter or look up payment times with that level of
precision.

https://www.pivotaltracker.com/story/show/67956896
Test refactor: ignore actions column.

It's not really what we're trying to verify in these tests, and the
action buttons are tested by pressing them.
Payment history: Delete payment.

https://www.pivotaltracker.com/story/show/67956896
Renamed misnamed test support file.

Double file suffix was harmless, but untidy.
Forgot to check in payment unit tests.