Version update: 0.6 becomes stable.

The 0.6 beta1 release is now considered stable, as no confirmed bug has been found. If you use 0.6b1 you can stick with this version and assume you have the latest stable.

Works in progres on 0.7. New features will include:
- iproute2 support for interface based detection
- update plugins support for beter integration with known dynamic DNS services