Private flag for the npm package JSON file.

Setting `"private": true` in the npm package JSON file makes npm
refuse to publish the package. More important to this project,
setting the package to private removes the warning about the repository
field that doesn't need to be there.
Login and register view cleanup/style fixes.

I can't help but shake the feeling that the logic in these two views is similar
enough to be in its own view helper. Even still, I'm reluctant to essentially
recreate Zend\Form\View\Helper\Form because that's what it would probably look like.

I welcome feedback as to what should be done here. (It's not a pressing matter.)
Set HttpOnly flag for session cookies.

Closes #87.

Setting the HttpOnly flag for session cookies (and just cookies in general) helps mitigate
the risk of a client-side script accessing the cookie [1]. An HttpOnly session cookie will
be used only when responding to HTTP requests.

[1]: https://en.wikipedia.org/wiki/HTTP_cookie#HttpOnly_cookie
Added empty option & moved user type on register form.

Closes #60.

Added empty user type option for the registration form, and moved the select input
to the top of the form.
A11y fix for register form. (See #60.)