kernel - Major bridging functionality added (bug fixes)

kernel - Major bridging functionality added (bug fixes)

* The root bridge was not taking into account the peer's weightings when
  calculating path costs.

  In order to do this the root bridge must use available peer info.  The
  peer info should already include both the local and remote's path costs
  since 'we' are the root, so our path cost will already be directly
  incorporated in the path cost the peer reports to us.

* Fixes issue where not-weighted path costs on root bridge were not
  synchronized with the weighted path costs of one or more of its peers.