Further optimized the sidebar layout. Also made the 'Disease' and 'Graph' statistics panels collapsable.
In addition to the collapsable panels, the entire right sidebar can now be shown / hidden. There is a button in the UI for this functionality, as well as a menu item in the 'View' menu and a shortcut (F1). This closes #24. Also, the 'Selected node statistics' panel is now visible only when there is a single vertex selected. Lastly, some final optimziations have been made to the layout.