Provides classes to display a frame around a
{@link org.nongnu.savannah.jcurzez.Window}.
To create custom frames, one has to implement
{@link org.nongnu.savannah.jcurzez.frame.Frame}.
When no frame is supplied to a window, the frame will default to
{@link org.nongnu.savannah.jcurzez.frame.SingleFrame}.