This work removes most references to XSeries from the LMS in an attempt to be more general. ECOM-5018.

2. Add site configuration overrides to theming/helpers.py
3. Move microsite.get_value from theming/helpers to site_configuration/helpers
4. Move microsite_configuration.microsite.get_value usages to site_configuration.helpers.values

The LMS continues to expect lowercased category slugs, while the Studio program creator now uses correctly cased slugs. Programs should be updated before this is released. Part of ECOM-5018.

Observed Problems:
1. Discussion categories and targets were missing
2. When imported over existing course Discussion IDs have changed unexpectedly - all posts were missing

Solutions:
* Parsing legacy discussion OLX
* Do not force exporting discussion ID

Observed Problems:
1. Discussion categories and targets were missing
2. When imported over existing course Discussion IDs have changed unexpectedly - all posts were missing

Solutions:
* Parsing legacy discussion OLX
* Do not force exporting discussion ID

TNL-5002

https://openedx.atlassian.net/browse/TNL-5008

Includes a refactor of the program data extension utility. ECOM-4807.

unawaz/ECOM-4787-account-settings-page-header

ECOM-4973

Part of ECOM-4566.

This is the first in a series of commits that will retrieve and use data from the catalog API. Part of ECOM-4566.

These changes unify four different approaches to JWT creation, moving the core of the AccessTokenView to a general-purpose JwtBuilder class. This utility class defaults to using the system's JWT configuration, but it will allow overriding of the signing key and audience claim to support those clients which still require this. Part of ECOM-4566.

Converts the dates on the dashboard, sidebar navigation, and important course dates to user specified time zone.

Refactor all S3 code to use the django storage API and add swift
settings for openstack deployments

Displays a message and link when a user is enrolled in a program's course run but must upgrade in order to be eligible for the program certificate. ECOM-4220.

This change improves grading performance by combining what had previously been
multiple course tree traversals into a single traversal with combined
filtering logic.

2. Update COMPREHNSIVE_THEME_DIR to COMPREHENSIVE_THEME_DIRS
3. Update paver commands to support multi theme dirs
4. Updating template loaders
5. Add ENABLE_COMPREHENSIVE_THEMING flag to enable or disable theming via settings
6. Update tests
7. Add backward compatibility for COMPREHEHNSIVE_THEME_DIR

* Renames discussion_module to discussion_xblock
* Moves common/lib/xmodule/xmodule_discussion to openedx/core/lib/xblock_builtin/xblock_discussion