Will clean up in a bit.

Also doing some cleanup.

- Also removing some unused imports and cleaning up code.

- Implement a &url= parameter and get_url_specific_results().
- Update tool description.
- Increase text box widths.
- "Markov chain size" -> "Trigrams"
- Don't show "The WMF paid Yahoo $X" if $X is $0.

This allows us to play around with the interface without actually
running checks just yet.

Still have to update bigrams to trigrams.