Placeholder Navigation Bar

Added a basic html list navigation bar, and corresponding css. Also
externalized some of the css in display.html into topology.css.
Move Slider & Add Tooltips

Moved slider to top right hand side and changed to vertical orientation
to make room for navigation bar.
Also removed node text labels and added names in tooltips instead.
Also changed a few constants so the nodes are not bouncing as much and
made circles scale correctly with slider.