[DEV]: Add possibility to use child model-descriptions with properties containing a namespace relative to the global `__namespace`.

 +Added unit tests for this use case
[DEV]: Added support of model-descriptions for child properties which are objects and not arrays.

+ Code change to guarantee better readability.
Merge pull request #7 from MadMG/master

Add possibility to use child model-descriptions with properties containing a namespace. 

Good to go - thanks a lot!