issue #456 - updated config schema
issue #456 - implemented api endpoint for theme enable/disable
Work in progress for theme selector
Merge branch 'issue/456' of github.com:adaptlearning/adapt_authoring into issue/456
Work in progress
Working version of theme picker functionality

This probably needs some styling, I'm not sure how far we want to take the
front end with regards to screenshots, etc.
Merge branch 'develop' into issue/456

Conflicts:
	frontend/src/adaptbuilder/css/adapt.css
	frontend/src/core/editor/page/templates/partials/part_editorCommon.hbs
Slight tweak to theme picker styling
Merge pull request #457 from adaptlearning/issue/456

Issue/456