Added ClippingOrganizer, Book, and Author classes to project
KindleClippings changed from Exe project to Library

- Removed Program class
- Made library classes public for reference by other projects
AssemblyFileVersion should now use the AssemblyVersion
KindleClippings classes/methods are all static now for ease of use
Added KindleClippingsGUI project.  Uses Eto.Forms for cross-platform compatibility.

- Currently available from GUI: Select file, parse, loads Authors, Books, Highlight/Note locations into TreeView
- TODO: Double clicking on items in the tree to view them in detail; icons