Rework how errors are output
Rework how errors are output

Changed the way we do errors, as throwing exceptions for any missing marker
is a bit overkill. Just log a error if both markers are missing, this is the
case of the user existing but not allowing logins. We would not get a env back.
For backwards compat we will just log this and let the cmd try to be executed.

Getting back just one marker indicates something went very badly with the Python
code and is worthy of an exception.

saltstack/salt,saltstack/salt,saltstack/salt,saltstack/salt,saltstack/salt