- added pre-existing helpers for dimentions display
- remove selection coloring completely for now
- added on screen display (overlay) for object position, rotation, size (not fully functional)
- changed "addToScene" to addImportedResource : now takes a resource as parameter,
and dispatches a newOperation event with an "Import" operation instance
- various minor tweaks all around
- changed loadResource method slightly : it now passes the loaded resource instance directly
to the visual editor's addImportedResource method