Various small changes and other clean-up.

• Changed the quick navigation menu to display on the side, and stay in the window, so it is always available. Also made it so that it slides in and out to take up less space.
• Added a button to hide the “hilite color chooser”, since it can get in the way sometimes. Clicking to color glyphs works even if the chooser is hidden. The button is at the top of the page, next to the navigation menu.
• Fixed the coloring of glyphs. Now it should work in Firefox as well.
• Various bits of technical clean-up. Hopefully I didn’t break anything. If something used to work and now doesn’t, feel free to leave a comment.