QRadioGroupBox and QCheckGroupBox with abstraction class

Add QAbstractButtonGroupBox class abstraction for the next class
Add QRadioGroupBox widget class
Add QCheckGroupBox widget class

Integration with deisgner
Add QCheckGroupBoxPlugin class
Add QRadioGroupBoxPlugin class
This member could be removed if the abstract class has a QAbstractButton* createButton() as protected reimplemented in the child class. Same for add.
So for me, insert/add should be in abstract class as normal member and depend a createButton() virtual member.