Changed prompt and about in language detection demo

@sonney2k: Changed the message of the language detection demo to state the available languages and the about to mention the classes used. This is what it looks like currently : https://dl.dropboxusercontent.com/u/23851310/Screenshot-shogun-demo.png. If you want something changed let me know.
@foulwall: If you don't approve of the way I bypassed autoescaping and you have another way for disabling it let me know!

On another note, I was thinking that maybe when the documentation on the site is updated we could link classes from the about to the site and/or the authors to their personal webpage or github.