[WIP] <oo-install> - Error handling improvements

- Add ptywrapper.py script
  - add ptywrapper.py script to remove the need to use a pty with the ssh session, since openssh redirects stderr to stdout when a pty is used.

- gem updates
  - update net-ssh to 2.9.2.beta to properly timeout when connections are dropped.
    - Currently using a locally built copy from net-ssh master, since the 2.9.2.beta gem hosted on rubygems does not include a needed fix. Once a newer gem is available we should update the gem accordingly.
  - add net-scp and net-ssh-multi

TODO:
- move ssh handling from host_instance to deployment and use net-ssh-multi to multiplex connections to the hosts instead of managing ssh sessions manually for each host.
- update scp command line usage to use net-scp (utilizing the host connections from net-ssh-multi).
- update ssh connections to not use a pty, and instead copy the ptywrapper.sh script to the host and run commands through ptywrapper.sh
- update error handling code to verify return code from commands and to display any stderr content on failure.
- enterprise and origin workflow script updates to support above changes.