* updating vendor files
* updating class syntax (to new FA-based classes) for all UI elements
* correcting broken tests

Introduction of the Microsite feature which allows for limited multi-tenant branding on a subdomain basis, e.g. foo.edx.org and bar.edx.org

fix errorenous logic when running a microsite that could reside in a hosting environment with a marketing site in front of it

pep8/pylint fixes

address PR feedback, remove underscore from test hostname

more pep8/pylint cleanup. Skip test_microsites test, it works on localdev, not on Jenkins. Need to talk with QA team

manually add Ned's single-to-double quote fix

change aws.py runtimes so that the microsite_dir that is read from configuration is changed to a python path

Conflicts:
	lms/templates/help_modal.html

- Make email field in forgot password modal aria-required = true
- Added Transcript skip links to both before and after the transcript
- Add language code to main.html so that screenreaders know what language/region to speak for

The close button for the modal dialog was marked up as a paragraph,
containing a graphical text character, inside two div elements, with an
associated click event. This made the button unusable for keyboard
users.

Replaced <divs> with a link element (<a role="button"), adapted the CSS
accordingly, and updated the existing <a> modal close buttons.

Also adding the email description to the login page and applying the
same aria attribute to the correspondin input on that page.

From LMS-602:

> There is additional explanatory text, marked up in a span element after
> the email input. The input elements should be explicitly associated with
> this additional text using the aria-describedby attribute. This will
> require an ID to be assigned to the span element.

Use the `PLATFORM_NAME` setting instead of "edX"