bird-2.0.x compatibility

[tamihiro]

bird-2.0.x compatibility

[zorun]

Thanks for the report, #38 has just been merged and should fix the issue in a more maintainable way.

[tamihiro]

I've just noticed #38 did fix parsing the output of show protocols but not of show route for <prefix> all and therefore build_as_tree_from_raw_bird_ouput() fails with exception.

Traceback (most recent call last):
  File "/usr/lib/python2.7/dist-packages/flask/app.py", line 1836, in __call__
    return self.wsgi_app(environ, start_response)
  File "/usr/lib/python2.7/dist-packages/flask/app.py", line 1820, in wsgi_app
    response = self.make_response(self.handle_exception(e))
  File "/usr/lib/python2.7/dist-packages/flask/app.py", line 1403, in handle_exception
    reraise(exc_type, exc_value, tb)
  File "/usr/lib/python2.7/dist-packages/flask/app.py", line 1817, in wsgi_app
    response = self.full_dispatch_request()
  File "/usr/lib/python2.7/dist-packages/flask/app.py", line 1477, in full_dispatch_request
    rv = self.handle_user_exception(e)
  File "/usr/lib/python2.7/dist-packages/flask/app.py", line 1381, in handle_user_exception
    reraise(exc_type, exc_value, tb)
  File "/usr/lib/python2.7/dist-packages/flask/app.py", line 1475, in full_dispatch_request
    rv = self.dispatch_request()
  File "/usr/lib/python2.7/dist-packages/flask/app.py", line 1461, in dispatch_request
    return self.view_functions[rule.endpoint](**req.view_args)
  File "./lg.py", line 369, in show_route_for_bgpmap
    return show_route("prefix_bgpmap", hosts, proto)
  File "./lg.py", line 665, in show_route
    detail[host] = build_as_tree_from_raw_bird_ouput(host, proto, res)
  File "./lg.py", line 594, in build_as_tree_from_raw_bird_ouput
    path.extend(line.replace("BGP.as_path:", "").strip().split(" "))
AttributeError: 'NoneType' object has no attribute 'extend'

Please review #45, which is actually #42 minus the first chunk of diffs.