Release SHA status information missing

This has been removed from Capistrano 3, and there's currently no way that I can figure out to accomplish the following:

* Get the SHA of the currently deployed branch. There used to be a `REVISION` file on the root of every release that you could just read. Not anymore.
* Get the SHA of the previous release, for comparison purposes.
* See what's not deployed yet, there used to be a 'deploy:pending' task just for that purpose, not anymore.

Your thoughts on this?