Code modified to use the new Range object for Rule

Issue: #43
Signed-off-by: Rossella Sblendido <rossella@midokura.com>
Merge pull request #45 from midokura/rossella/master

Code modified to use the new Range object for Rule
Fixes #590: Set MTU size to 65021 when creating TAP interface.
Merge remote-tracking branch 'upstream/master' into issue-590