- fixes for saveState / restoreState (better handling of custom parameter classes)
- added method GroupParameter.setAddList
- ListParameter now remembers its value even if its list is cleared and rebuilt
- added ActionParameter (buttons) and TextParameter
- fixed handling of foreground colors in AxisItem
- fixed rare crash caused in AxisItem
- fixed improper propagation of key events from SpinBox
- many others
GraphicsObject - corrected bug in viewPos() method
WidgetGroup - allow bound methods in interfaces
parametertree - fixed crash when calling remove from context menu