Implement caching

cURLing from remote URL on every page request is not very efficient. Most of the remote content is more or less static so it makes sense to cache content once cURLed.

I can see a dramatic speedup and much lower overhead with such a solution.

![toxidcache](https://cloud.githubusercontent.com/assets/15139/4925519/b16eef2e-652b-11e4-8576-e435c80aaa63.png)

Cheers! … und Grüße nach Magdeburg!