Improve options page (realtime display)

Realtime Options Page Display
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- A static Jetzt instance shows the UI of the Jetzt view with a realtime-updating font display and colorization.
- Light/Dark selection, with choose-your-own-color `color` input.
- Pick your own progress-bar color
- Light theme whites out background, dark theme blacks it out
- A dummy paragraph color-coded to show the different pause types

Screenshots:

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![capture](https://f.cloud.github.com/assets/693511/2433125/a2ebd950-ad82-11e3-9415-430b417b1888.JPG)