Begin vconfig implementation, starting with get_realdev_name.
add_vlan, del_vlan. get_vid, get_realdev_name
Allow vconfig.get_realdev_name() to be used without creating an object.
Allow get_vid() to be used without creating a VlanInterface object.
Merge branch 'master' of https://github.com/rlisagor/pynetlinux
Update route.py

add a get_interface_gw
merge Denton Gentry's VLAN configuration code
merge Matthew Stone's bridge.set_stp_mode()

cherry-picked commits ab46f27..d8f08fa
(from https://github.com/bigmstone/pynetlinux)
merge Gabriel Rota's get_interface_gw()
use relative imports (not only for Python 3 support)

cherry-picked
https://github.com/rhgrant10/pynetlinux/commit/e7045d95080dd5c8d1973e06d054426e9242d5c4
as basis