Auto generating start and end slides

Heya Felipe,

I've added some code to automatically have the start and end slides generated by power-polygon.

The start slide is generated by taking the content of title, author and dcterms.date elements in the head of the document.

The end slide puts the question-mark from font-awesome in the centre of the page.

If you decide to take this up into the code i will update the documentation in the wiki accordingly.

Mazzel,

Martijn.