- uniformise color of every interactive controls of the curves and stitch

  OE_actionScaleSelectedStitchLen
  OE_actionScaleSelectedStitchWidth
  OE_actionSetSelectedStitchPattern
- fix memory leaks when deleting meta actions:
  OE_actionScaleSelectedBirailStitchLen
  OE_actionScaleSelectedLineStitchWidth
  OE_actionScaleSelectedLineStitchLen
  OE_actionSetSelectedLineStitchPattern
  OE_actionSelectionClear

- 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

- fix a pan problem (2 time slower than the mouse move)
- add a backgroundColor in displayStyle

- fix a pan problem (2 time slower than the mouse move)
- add a backgroundColor in displayStyle

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

- add OE_actionDelPointLinkStitch and make it work

- make linkStitches point pickable

- add actions for stepPoints functions

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

- add a lot of displayStyle variables

- make first and last point move together when form is closed

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