Removes most remaining hardcoded references to XSeries from the LMS. Part of ECOM-4638.

ECOM-4398

ECOM-3729

Updated dashboard UI for empty list of courses and programs

Updated dashboard UI for empty list of courses and programs

This reverts commit 628843f6.

Updated dashboard UI for empty list of courses and programs

remove unnecessary parentheses

change css properties for mixins bi-aap in login/register page

change css properties for mixins bi-app in about course page

change css properties for mixins bi-app in the dashboard

change css properties for mixins bi-app in help template

change css properties for mixins bi-app in the home page

change css properties for mixins bi-app in jobs, press and media pages

remove the extra spaces

- Icon images can be uploaded from the django admin
- Test coverage improved

- Icon images can be uploaded from the django admin
- Test coverage improved

It looks like in the past there used to be several tabs on the
course about page, but the other tabs have been commented
out years ago.

Having a single tab is pointless and confusing, so remove it.

Move tests to one test class

ECOM-3015

This reverts commit 46df4545, reversing
changes made to 039e6cdf.

ECOM-3015

- Simplified logic determiningg credit messaging on dashboard
- Fixed bug preventing users from initiating credit request

ECOM-2893

ECOM-2435

- Added support for Unicode characters when creating the signature
- Using <textarea> for form data to support newline characters
- Generating form with jQuery instead of relying on existing DOM element
- Removed duplicated credit request code
- Corrected spaing on dashboard
- Enabled functionality by default

Dashboard cleanup
-- Cleaned styles
-- Added wrapper class to use for hiding the actions
-- Cleaned JS toggling of error container
-- Corrected dashboard and receipt text

ECOM-2172

ECOM-2338