Try to ensure we are logged into a Unix system before proceeding too far

Argggh, git diff....This diff looks a lot messier than it really is....Added an if statement and therefore almost all the code got indented.

Basically:
**Line 1**: Added a hashbang
**Line 127**: Check to see if we actually have a hostname before assigning it to devargs
**Line 130**: Wrap the rest of the code in an if statement, so that if we have an empty hostname, we don't run anything else, and can assume that we SSH'd into a non-Unix device (i.e. an SSH capable switch or some such)
**Line 269***: Print an error at the end of the if statement saying that this is likely not a unix system as we couldn't get the hostname

There were also a few places where I changed:
*print machine_name*
TO
*print str(machine_name)*