CouchElephant 1.4.0

The second cleanup review, over the routes, the alerts and the rest of the app.

Fixed

• Alert times ignored the timezone setting. Every "a pass booked a
  recording at ..." line was formatted with the container's clock rather than
  the zone the app is set to. It is the one time the product quotes outside its
  own pages, and it was the one time that did not honour the setting.

• The useful error message was on the path nobody takes. Sending and the
  Test button each carried their own list of what a destination needs, worded
  differently, and the better sentence was on the button you press once. The
  settings page renders the error from the hourly send, so the sentence you
  read when something is actually broken was the worse of the two. A bot with
  no channel now says where to find the channel id, wherever you meet it.

• A smart pass with no name read as blank in the schedule row, the guide
  panel and the failure panel. Four places spelled the label out instead of
  calling the helper that describes the filter when there is no name.

• The announced search wrote to the passes table directly, bypassing the
  one function whose docstring calls itself the only place a pass is written,
  after the previous three had drifted apart. It was the fourth.

• One route answered a failure with HTTP 200, leaving the client to work it
  out from the body alone.

• A fault code was raised as a bare string rather than its constant. Correct
  today, silently broken on a rename, and now checked by a test.

Performance

Measured against the live scale: 16,700 programmes, 22,800 airings, and a
60-day history.

• The schedule is about four times faster. It ran the most expensive query
  in the app twice, the second time to count rows for a number no page renders.
  One row more than asked for answers the same question. The failure half also
  sorted the whole history to answer a question about broadcasts that have not
  aired yet.
• The filter panel counted genres and teams by parsing every programme's JSON
  in Python. SQLite reads it directly, guarded so one malformed row cannot take
  the panel down, which is the behaviour the Python version had.
• Guide search folded each title once per broadcast rather than once per
  programme.

Removed

Four pieces of dead code: a route nothing calls, an unused import, a helper
that only its own recursion used, and a function written for a provider that
was rejected and deleted. The sports source also asked its API twice for one
row, against a rate-limited free tier.