update the readme

- remove the OE_commandDisplay class (specific functions are merged in OE_diplay)

- store the len value of the birailStitch
- add the move function to staticStitch
- add getStitchStart and getStitchEnd method to OE_linkstitch
- fix a bug in OE_linkstitch::refresh method (it always put needRefresh to false)
- add double point motif to OE_linestitch
- add OE_actionDelStitch
- fix a bug in refreshDependency of most stitches and curves (does not refresh dependency of their own dependency)

- add a refreshDependency function to refresh every dependency link (execute addDependency(this) in each parent of a child)

- 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

- create an actionSelection only when there is a selection

- replace the array (curves, stitches, threads,...) by list to be more flexible with delete and moves of elements
- refresh curves only when needed

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

add a new subcurve class (parametric subcurve) and a joincurve (concatenate curves)