This reverts commit aaa2788e, reversing
changes made to 80b74762.

This gets us to 100% code coverage.

Adrian Greeve authored Oct 10, 2016 and Jake Dallimore committed Oct 26, 2016

Added a function for checking if a domain is allowed
against a list of domains that could contain wildcards.

New library providing utilities for IP addresses, DNS and other
internet-protocol-related information.

This also fixes the unit test to use the correct indices.

The initial approach I took was to provide a noscript area containing the
standard input element, and to move it to a hidden input element as part of
the passwordunmask setup.

This allowed behat tests to pass both with and without JS enabled (i.e.
with Goutte and real browsers), and also ensured that the real input did
not appear on screen.

However, the standard formslib validation occurs before other page JS is
run and hooks into the elements on page during its setup.
Since noscript elements are not accessible to scripts as standard elements,
the form validation would fail for _client_ side validation and work for
server-side validation.

This change creates creates the hidden input element in the template
instead, as well as the password element in the noscript tag.

Doing this means that when JS is disabled, the form has two elements of the
same name - one hidden, and the second a visible password field.
Since the latter element will always override the former one on form
submission, and the noscript variant is last, the noscript variant wins
when JS is disabled and tests continue to pass.

When JS is enabled, the noscript variant is not a valid part of the DOM
(the browser sees it as a hidden text field essentially). The password is
not automatically entered into the hidden field, so the autocomplete
prevention continues to work as expected.

This commit change send course welcome message to a drop-down that now supports sending emails from:
- Course contact
- Enrolment key holder
- No reply address
Also moves part of the logic of handling send welcome email from to a new method get_welcome_email_contact() and unit test for this new method.

This throws and exception which is caught - and the renderer fall back to the
legacy HTML for the element.

originalcourseid matches coding style