* Evaluate %h and %u before deciding if the ssh config path is absolute
Since %h is the user's home directory, it's not very useful unless it
appears at the beginning of the path. However, putting it at the
beginning of the path does not have the expected effect: %h/.ssh
will become /home/someuser/home/someuser/.ssh, since "%h/.ssh" is
identified by Python as a non-absolute path, causing the user's
home directory to be tacked on the front.
* Improved ssh_auth path expansion test