add closeParent property to TabbedPane, so the last closed Tab won't
dispose the parent view.

This has to be configureable, because sometimes you have still a window
with a nice menu or other stuff + a disposed window won't quit the
application in every situation.

v2: rebase on master
make openPath and closedPath protected
this will allow additional drawing like alpha masking or other overlaid
stuff
add some creatIcon methods to custimizing the size
set UI class only if there isn't any
this will help a lot if the DefaultTab class is loaded very early (after
the global LookAndFeel was loaded)