Revert "Clean up unused / duplicate imports, etc."

This reverts commit cbd695a4451403aad7f4eff7cce2eaeff4256eb8.

The new naming of the argument "route_type" is incompatible with havana.

Signed-off-by: Joe Mills <joe@midokura.com>
Merge pull request #200 from JoeMido/revert_route_type

Revert "Clean up unused / duplicate imports, etc."