refactor first class windows to allow embedded views of AlignFrame in SplitPane

The current desktop window model has JFrames containing action listeners bound to statically created Jmenus. The upshot of this is that for compound displays like the SplitPane, where two distinct alignment views are shown in the same frame, the whole JFrame has to be embedded.

Controller code, UI generation code and state needs to be factored out of the concrete JFrames added to the Desktop content panel so that an AlignmentPanel (with or without menus) may be rendered within any arbitrary JPanel.