Unfortunately disabling IPv6 via sysctl doesn't actually
disable it on all of the interfaces by default. Disabling
it via grub disables it entirely in the VM.

Helps with #454

Also report connected in standalone/bridge mode

Fixes #460

Conflicts:
	mininet/node.py

Basically no changes except for whitespace and satisfying pep8.

(Also untabbed comment lines, flagged by emacs et al.)

Future versions of pylint will allow this to be disabled
in the file itself, so we can drop the limit back to
1500 or something more reasonable!!

Maybe this is better - maybe not. ;-p

Usually you won't want to create a node in the root namespace,
and usually you won't want to use the Mininet API to set your
(real) default route, but if you do then you will probably want
to use a single command line to avoid disconnecting an SSH
session while we wait for the reulst of the 'ip route del default
command.

update examples README with new examples

Updating NAT class to use gateway interface

Also, passing CLI args to NAT constructor

fixes #437