Merge pull request #152 from koreno/parallel

Parallel updates: Added ClusterSession, and allowed args in popen
Disallow piping/redirecting of paramiko-machine commands.

Close #155, #50
Merge pull request #160 from koreno/155

Disallow piping/redirecting of paramiko-machine commands.
Windows: hide window only for executables of the console subsystem. closes #161
Implemented BaseCommand.iter_lines
Merge pull request #163 from koreno/iter_lines

Implemented BaseCommand.iter_lines
Merge branch 'master' into parallel