Kindle specific view for the Content Server

Hi,

this is still a Work in Progress but I wanted to get some feedback on this before.
This is a Kindle specific view for the Calibre Content Server because the mobile view was sadly a bit of a mess on my Kindle.

I started by taking the normal mobile.py and duplicate it to kindle.py and work my way from there.

On top of that I've decided to filter away formats that the Kindle cannot show and just display the one's it can.
It starts by doing a ```format:mobi OR format:azw3``` search query and then afterwards on URL generation for the Download again only showing the relevant formats.

I've also made it possible to directly search for an Author, Tag or Series through the use of normal hyperlinks.
And because sometimes you want to see a Summary (but not always) this is Toggled through a simple Javascript command (which the Kindle supports! hooray!)

I'd love to hear some feedback, I haven't done Python in a while so don't go completely bonkers on me ;)