WIP
Misc SSH fixes/improvemnts

- Reformatted the SSH SHIM script to be readable
- added more pythons to SHIM
   - RHEL python altinstalls are ...2.x not 2x
- added tty params around to allow tty specification in roster
- TTY=True is not working, see TODO
- Replaced "sudo -i" with individual "sudo" invocations in the SHIM
  - supports systems where exec'ing a shell with sudo is forbidden
  - Also precludes tainting environment with users login shell
- Added some more SSH options per salt.cloud (@s0undt3ch)
Merge pull request #7557 from ajithhub/ssh_fixes_for_rhel

Re: ISSUE #7528 Various salt-ssh issues regarding passwd and RHEL support