update the readme

Qt port: fix controller document, fix keyboard modState, fix key event redirection, fix last tab close bug, fix menu emulated shortcuts, add pakal to build

- 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

- add actions for moves
- add - operator to vector_2d class

- add some actions to clear selections

- add editLastAction function to OE_controller to make possible "live modification"
- add OE_actionSetPointCurve and OE_actionMovePointCurve to OE_actionCurves
- add setPoint function to OE_pointcurve and change getPoint to use reference instead of pointer