v2.0.0

This is the first release of the new Data Commons Repository! (Formerly
"Mirrors".) This version has a lot of changes both on the front end and
the back end.

Enhancements:

• App front-end rewritten in AngularJS.
• Refactored to use DE Terrain API for file metadata instead of querying
  python-irods to query iRODS directly.
• Direct downloads are (when supported) are offloaded to the CyVerse
  anon-files service. This frees up the DCR server to continue handling
  web requests and not be responsible for managing download streams from
  iRODS. Direct download is supported for files up to 2GB.
• Much improved file previews. All text-like files can be previewed up
  to 8kB. Currently supported previews include files that Terrain
  reports content-type text/*, e.g., text/csv, text/plain, etc.
• Prototype landing pages that display combined template metadata and
  iRODS AVUs.