- is_*() returns True if the interface name is of a certain type
is_bondethernet() is_loopback() is_bvi() is_bridgedomain()
is_vxlan_tunnel() is_phy()
- get_phys() by process of elimination, returns all interface names
that are supposed to be physical network interfaces.
Add unit tests for validator/vxlan_tunnel.py
=> Notable: while here, fix a bug in get_by_name()
Add unit tests for all the is_*() and get_phys() functions.
They now all return a list [ifname, iface]. If no interface was found
they return None,None. If one was found, they return the (string) name
and the dictionary with interface contents.
