shaded jars should be removed from <dependencies>

- updated shade plugin version (got strange exception during clean install with maven 3.1.1) 
- removed promoteTransitiveDependencies=true because the whole point of shading is to reduce dependencies (and there are no transitive dependencies that we're not shading)
- removed shadedArtifactAttached=true, this one seems to cause the shade plugin not to remove the shaded dependencies

Overall i think this results in a more correct release. The way it is now is not wrong but one does not expect shaded jars to be still dependencies, it's the whole point of shading after all.