added sub-panel resizable option...

Signed-off-by: Alex A. Naanou <alex.nanou@gmail.com>
refactoring and tweaking...

Signed-off-by: Alex A. Naanou <alex.nanou@gmail.com>
base panels almost done, some minor polishing left...

Signed-off-by: Alex A. Naanou <alex.nanou@gmail.com>