- fix problems on linestitch interactive creation

- add creations function
- change functions in joincurve class to insert new curves anywhere and remove them
- add an action to create and add a subcurve to a joincurve

- add function to drive the embroidery hardware
- add a background grid into the editor view
- add a new motif into linestitch

- add start command
- in commanDisplay there is no more bug with the color of the first stitch

- add instructions class
- add hoop, pulse/mm and zero point in document

declare dependents objects to their reference (to be able to remove the reference without error)

- draw controls only for the selected curves and stitchs