New help panel that slides in from the top and pushes the content ...

Created by: anaqreon

…down so it is not covered. Panel toggles with help button. Still some bugs with small screen viewing.

Just noticed a bunch of indentation changes in nav.tpl that got in there somehow. All I did substantively to that file was change the onclick behavior. I didn't do any of the indentation changes intentionally. use git diff -w blah blah to simplify this diff view. What's with the 100-space tab stops anyway?