Valentin/fix stuff

First round of improvements.

The diff looks big, because I nuked the ``cache`` directory and the ``.doit.db`` as suggested on:

https://groups.google.com/forum/#!topic/nikola-discuss/luF6pyO5Jo4

Also I renamed ``Blosc More In Deep`` to ``Blosc in Depth`.

Other things are minor rewordings and syntax improvements.

I think this is a good first iteration, there are still some things, repetitions, sections that might be confusing etc.. but I think it's good to go!