RiverLayout is a flexible, yet very easy-to-use
Java layout manager. RiverLayout is inspired by
the way HTML formats text. RiverLayout is similar
to FlowLayout in the sense that the UI components
flow, usually from left to right, as they are
added to a container, but control strings like
"br", "tab", and "p" can be used to better adjust
the location. For instance, the "tab" string
greatly simplifies the construction of forms.
