Remove an extra newline

Introduced in work on #70
Make wordpoints_debug_message() a wrapper

Just call `_doing_it_wrong()`.

See #70
Add `@expectedIncorrectUsage` to unit test

No more `@`error silencing!

See, we’re getting benefits from stuff built around `_doing_it_wrong()`
already.

See #70
Split the db.php test cases into separate files

Provoked by work on #70
Improve type coherence in WordPoints_Points_Hooks

See #60
Simplify the _prepare_posint__in() method

Scrutenizer thinks it is ugly, and yeah, so do I.

See #60
More specific types in docs

See #60