Add ability to mount volumes in readonly mode using -volumes-from
Closes #2328 - allow the user to specify a string timestamp (not just a unix epoch) in the string format that the docker cli shows to the user
Merge pull request #2348 from SvenDowideit/2328-docker-events-since-date-string

Use string timestamp for docker events -since
Merge branch '1887-allow_ro_volumes-from' of https://github.com/daniel-garcia/docker into daniel-garcia-1887-allow_ro_volumes-from