Python 3 compat

Merge pull request #1 from eborisch/python3

Python3 updates

Streaming stores.

This release adds the ability to stream the output of a command to a file on the remote destination. For example:

import os
import subprocess

(r, w) = pipe()
proc = subprocess.Popen(['rsh', 'server', 'cat', fname],
                        stdout=os.fdopen(w, 'wb', 0),
                        stdin=open('/dev/null', 'rb'),
                        stderr=open('fetchlog.err', 'w'),
                        universal_newlines=False)
sendFiles['{0}'.format(r)] = remote_file(fname.split('/')[-1])

will execute (via rsh) 'cat' on 'server' of the path fname, with the output placed into the file-part of fname in the remote destination directory without staging to the local filesystem.

Bugfixes

Bugfixes to ar_lib/ssh.py when run as (testing) script.

Initial release

Created for ISMRM OSS Tools Session