LazControls: New files for CheckboxThemed.

git-svn-id: http://svn.freepascal.org/svn/lazarus/trunk@47029 4005530d-fff6-0310-9dd1-cebe43e6787f
LazControls: add component CheckboxThemed made by Vojtech Cihak.

git-svn-id: http://svn.freepascal.org/svn/lazarus/trunk@47030 4005530d-fff6-0310-9dd1-cebe43e6787f