update the readme

- add an stitchPostProcess method in OE_stitchs to handle every post modifiers (maxLen, stretch,...)

- fix a bug in OE_fillstitch due to error in detection of intersections between some stitch patterns and patch contours

- move curves handles when we set a grid control point in OE_fillstitch

- add an option to warpStitch method to use 2 lines instead 1 line and 1 normal array

- add some "const" in utils.h

- add save and load of linkstitches steppoints in .oe files

- make linkStitches point pickable

- add actions for stepPoints functions

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

- warpStitch include now x and y offset for pattern translation
- add xOffset and patternSteps attribute to linestitch and rename offset to yOffset

- add OE_controller::getSelectionBoundingBox function
- rename "select" function to "picking" in OE_interfaceDisplay (more clear name)
- change selection mode into an editionState in OE_interfaceDisplay
- add scale method to curves and stitchs
- add ScaleSelection state and implement the scale selection actions and UI widget
- clean and comment OE_interfaceDisplay
- add BoundingBox::getCenter method
- add OE_display::screenToDocument method

- 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 actions for moves
- add - operator to vector_2d class

- display the bounding box of the selection

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