core: better logging around locks
providers/virtualbox: no SSH info if not running
providers/docker: docker-run command starting points
core: Fix bug where if outputting empty string, would output nothing
providers/docker: stream data for run
providers/docker: fix some extranneous newlines in streamed output
providers/docker: run_command doesn't need to actual setup host machine
providers/docker: expose ports
Merge pull request #3560 from mitchellh/f-docker-run

docker-run command