added highlight.js to support syntax-highlighting, added cli-option to change highlight-css-files
check if language exists in highlight.js
removed auto-guessing when lang is not detected by highlight.js
highlight.js only uses lowercase names
switched to pygments because github is using it, changed css to accomodate the pygment-switch
lowercasing the lang-name
Merge pull request #2 from TN1ck/master

Pygments highlighting