Page skeleton and endpoint to submit FA requests to Zendesk.

ECOM-2824
ECOM-3038

Discussion forum styling cleanup to correct current visual styling issues in addition to cleaning up styles in preparation  for adding post images

* Add new role for support staff.
* Move dashboard/support functionality into a new Django app called "support".
* Add support view for searching and regenerating certificates.
* Refactor certificates views into separate files.

Also reconfigured paver to compile Sass into CSS directories

Serve branded footer JSON/HTML/CSS/JS from an API endpoint
in the branding app.  Refactor OpenEdX and EdX.org footer templates
to use the Python version of the API, ensuring that the API
values are consistent with the footer included in main.html.

Detailed changes:

* Added footer API end-point to the branding app.
* Footer API allows the language to be set with querystring parameters.
* Footer API allows showing/hiding of the OpenEdX logo using querystring parameters.
* Deprecate ENABLE_FOOTER_V3 in favor of the branding API configuration flag.
* Move no referrer script into main.html from the edx footer template.
* Rename rwd_header_footer.js to rwd_header.js
* Cache API responses.

Authors:
Awais Qureshi, Aamir Khan, Will Daly

ECOM-1547 created new template and Sass file for new footer. Wrapped it in a feature flag and updated previously named footer-edx-new.html to footer-edx-v2.html to better track/name updates to the footer going forward.
ECOM-1547 removed data-updated attributes from body
ECOM-1548 added JS file that inits analytics event listener and makes ajax call to API to get footer and HTML and add it to the DOM
ECOM-1547 code review cleanup
ECOM-1547 rebase and Sass appraoch update after @talbs the IE9 killer slayed the mighty beast.
ECOM-1547 updated file names and added comments in light of @talbs review of PR
ECOM-1547 update to social media link styles and nav link order
ECOM-1547 updated SOCIAL_MEDIA_FOOTER_NAMES if ENABLE_FOOTER_V3 is true
ECOM-1547 added translations to screenreader text
ECOM-1547 fixed test and renamed files in line with @talbs's pending PR
ECOM-1547 cleaned up file naming

TNL-1499

* provides new .scss file for developers to add temporary/in-progress Sass for further refactor/polish
* cleans up note/import order in all application scss files

With tests, some settings changes
(all should default to not breaking anything for edx)

Added styling for shopping cart User Experience
- Styled shoppingcart list page
- Styled navigation shopping cart button
- Styled receipt page
- Styled course about page for shopping cart courses

Addressed HTML/SCSS issues

Remove offending body class and unnecessary sass changes

Addresses many review comments on stanford shopping cart

* framework for generating order instructions on receipt page
  in shoppingcart.models
* move user_cart_has_item into shoppingcart.models
* move min_course_price_for_currency into course_modes.models
* remove auto activation on purchase
* 2-space indents in templates
* etc

revert indentation on navigation.html for ease of review

pep8 pylint

move logging/error handling from shoppingcart view to model

Addressing @dave changes

basic shell for home page exists, along with start of color cleanup for the rest of _discussion.scss

cleaned up font-awesome integration to work with new mako file .scss compiling, added in initial icon references

Two endpoints are intended to be used by AJAX calls from the web UI with an
authenticated user. When enabled, the value of the preference is an encryption
of the username, to be used as a token for one-click unsubscribe links. The
third endpoint is the target of unsubscribe links, which displays a page with
an appropriate message to the user.

cleaned up font-awesome integration to work with new mako file .scss compiling, added in initial icon references

cleaned up font-awesome integration to work with new mako file .scss compiling, added in initial icon references

Since the theme Sass is just a simple variables overrides (for the
moment), it must be imported right after the default variables Sass
file (if at all). At the bottom of the file, it has no effect.

cleaned up font-awesome integration to work with new mako file .scss compiling, added in initial icon references

If the `THEME_NAME` environment token isn't defined, then the
application.scss.mako file will crash during preprocessing. Use
.get to avoid a crash.

This commit adds the requisite settings and startup features to
enable integration of themes into the edX platform. It does not
yet provide hooks in any of the templates, but it does cause the
main `lms/static/sass/application.scss` file to `@import` a theme's
base Sass. Template hooks will come down the road.

CHANGELOG
---------
Define a new `MITX_FEATURE`, `USE_CUSTOM_THEME`, that when enabled,
can be used in templates to determine whether or not custom theme
templates should be used instead of the defaults.

Also define a new setting, `THEME_NAME`, which will be used to
locate theme-specific files. Establish the convention that themes
will be stored outside of the `REPO_ROOT`, inside the `ENV_ROOT`,
in a directory named `themes/`. `themes/<THEME_NAME>` will store
the files for a particular theme.

Provide a function, `enable_theme`, that modifies the template and
static asset load paths appropriately to include the theme's files.

Move the main LMS Sass file to a Mako template that conditionally
`@import`s the theme's base Sass file when a theme is enabled.

Add logic to the assets Rakefile to properly preprocess any Sass/
Mako templates before compiling them.