Clean up

Hi,

I removed much clutter, backup files and so. I also started with the removal of stuff that isn't needed for slicing (such as the Printer interface and the Extruder interface: we will ever need only the G-Code implementation of those interfaces).

My intention is to make my clone a pure and simple slicer alternative in java. (But not an alternative for pronterface).

Best regards,
Holger.