Initial attempt overhauling model

Made me go back to white board
Updated XmlData with new getter and setter

Other classes are just adapted in order to compile, not to work
Marching towards better model
Plugged model and main controller back together for debugging
Toggling work-tasks finished
Model done, improving editor now
Watching Big Bang Theory, no time for comment
Editing finished. About to add validation
Updated translations with text from editor
Finished editor
Merge pull request #1 from drunk-on-pain/Rework-Model

Rework model