Added a lot of documentation, more stream lining, should now work completely without having to define types but offer the same/more functionality than before. Backwards compatible too.
- File management is prepared to support folders (UI still lacking support)
- STL files are now first class citizens
- can be managed via the file list (and filtered from it)
- can be sliced on demand
- Slicing now happens via plugins
- Added Cura plugin
- uses CuraEngine directly instead of full Cura installation
- Cura profile importer for importing profiles from regular Cura installs via settings dialog
- TODO: UI for editing profiles
- API for slicing and slicing profile management
