Major architecture rehaul, with potentially breaking changes:
* alternate storage drivers are now implemented as independent pip packages in their own github repositories
* mainline docker-registry now only provide file and s3 storage
* all dependencies have been upgraded to the latest available version (specifically flask, gevent, bugsnag)
* updated and cleaned-up Dockerfile now uses latest Ubuntu LTS
* largely enhanced configuration mechanism (setup-configs.sh is no more)
* cookies are no longer used
* CORS is now enabled on a number of endpoints
* extras requirements
* Cloudfront redirect experimental support
* [BUGFIX] unicode issues. Depending on the storage driver you are using, you may encounter unicode issues on already published content (likely garbled content).
* [BUGFIX] content-length fix for bytes ranges
* [BUGFIX] tar not being seeked back to 0 after lzma read attempt
* [BUGFIX] inconsistent cache-control headers