Implementing some more of the API.

* Pagination is now rigged up.
* Content can now be fetched and deserialized.
* Content comments can now be fetched and deserialized.
* Rename data structures. No need to prefix everything with "Fakku",
that's why we have namespaces.
* Merge /Internal/Client.cs into /Fakku.cs
* Dropped HTTP support. This library only supports HTTPS.