MA-85 CMS REST API for video_upload.
Advanced Setting for "Video Upload Pipeline".
Feature Flag for "ENABLE_VIDEO_UPLOAD_PIPELINE".
New video uploads page
Use AssetMetaData store to persist video upload information.
Support for testing with real S3 servers.
Unit Tests.
Fix pylint errors.
General Feature Flags section in devstack.py.
Initial patterns for video uploads

Including progress and drag and drop space
Fleshing out patterns for video uploads
Tweaking based on PR comments

@talbs @frrrances
Merge branch 'mobile/studio-video-upload' of https://github.com/edx/edx-platform into mobile/studio-video-upload

This reverts commit c6db2e16e90d24176a56784bdfd367413e162958.