hwinfo: re-introduce listing of disks
hwinfo: enhanced error handling

If class is missing on the server, hwinfo script will now continue to display
the rest of the available info.
hwinfo: print output continuously

Don't wait for the complete output to print it, but directly interact with the
TableFormatter during processing the output.
Merge remote-tracking branch 'upstream/master'
system: enhanced error handling

If class is missing on the server, system script will now continue to display
the rest of the available info.
system: print output continuously

Don't wait for the complete output to print it, but directly interact with the
TableFormatter during processing the output.
hwinfo: use colored output only for tty
system: use colored output only for tty
hwinfo: deleted python.rst and updated doc
system: removed python.rst
Merge pull request #107 from pschiffe/master

hwinfo: re-added disks, little bit of refactoring