Configure whether highlight.js will guess syntax

- Upgrade to latest higlight.js (only common syntaxes)
- Upgrade highlight.css to reflect changes
- Default to no guessing
- Add corresponding guess and noguess loaders
- Loaders style the entire pre for better looking html
Don't use negative settings logic

- Default to guess language
Merge pull request #206 from facelessuser/master

Configure whether highlight.js will guess syntax