Fix CSS of the speedreading popup.

Needs to define a lot of properties so as not to be influnced by the
page's already existing CSS.
Red border for the popup when paused
Switch to jquery templating plugin (jquery-el)
Modularize settings for the speedread function
After getting to the end, reread it at speed /= phi
Alt+plus and alt+minus to jump + or - a  speed level
Remove the paused check on forward/back navigation
Fix the back arrow bug
Color-coded borders for the current reading speed