cleaning up
refactore core module until all tests pass
adjust test cases to new core structure
categories

* create a skeleton for the category handling
Category attribute adjustment

*adding default method for all array refs
*using auto_deref for better handling
little improvements

*not mentionable
adding controller module

*first skeleton of the controller module
*provides an array of categories and a lot of getter methods to access the
category items
*provide tests for controller module
substitude old readme file