Introduce a class inspired by subprocess.Popen that handles
running a command on a remote machine and handling its output.
To separate stdout & stderr streams of a remote command,
they need to be read in parallel, so that one of them doesn't
stall the runner when its buffer fills up. Accomplish this
by using a thread for each stream.
Part of the work for: https://fedorahosted.org/freeipa/ticket/3621
Add methods to run commands and copy files to Host objects.
Adds a base class for integration tests which can currently install
and uninstall IPA in a "star" topology with per-test specified number
of hosts.
A simple test for user replication between two masters is provided.
Log files from the remote hosts can be marked for collection, but the
actual collection is left to a Nose plugin.
Part of the work for: https://fedorahosted.org/freeipa/ticket/3621