This way there won't be two concurrent jobs trying to slice to the same file, which would practically render the cpu cycles from any slicing jobs than the final one wasted. Also adds a new event "SlicingCancelled" that will be sent in these cases.
- 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
Changed some endpoints again (removed "/control" path element) and made API spit out only raw data (e.g. seconds, millimeters, unix timestamps etc) instead of formatted versions. Modified frontend to take care of formatting this data itself.
