Improved namespace prototype chain creation.
Improved namespace prototype chain creation.

To create the namespaces in a prototypechain, previously a `Namespace`
constructor was used, of which the `prototype` property was constantly
reassigned for each newly created namespace.

By using `Object.create()` this is no longer necessary, with cleaner
code as a result.

pixeleet/virgilio,lucamaraschi/virgilio,icemobilelab/virgilio