fix policy version for ubuntu
Update Ubuntu port to 2.0.21 and the latest Ubuntu SDK

This updates the Ubuntu port to use the latest Ubuntu SDK components
and creates a new release of version 2.0.21. As location support works
now reliably on Ubuntu for a while, that has been enabled in the
Ubuntu too.
Merge pull request #136 from mzanetti/master

Update Ubuntu port to 2.0.21 and the latest Ubuntu SDK