ipdb: initial commit for routing management
iproute: get particular route
ipdb: incapsulate nla_fields into the Interface class
iproute: break too complext statement in get_routes

To ease debug
iproute: new route interface, +set command

Though compatible with the old one, it accepts now raw requests like
link routine does. Also, 'set' route from now on is possible too.
[UNSTABLE] ipdb: routing infrastructure, alpha version

Obs! This commit is NOT stable and it HAS issues. Refer to the code
and run tests to reproduce.
ipdb: start transaction for a new route
ipdb: split command and data nonce pools
Merge branch 'master' into ng

Conflicts:
	pyroute2/netlink/iproute.py
ipdb: fix race condition in route commit