Cleanup PDF Output

[Daltz333]

I think the PDF output can be improved in a number of ways

• Reduce/Remove the amount of warnings in generation
• Code blocks can sometimes break weirdly in PDF generation
• Images will sometimes span over text

Note: While PDF and EPUB are generated, I wouldn't exactly call them supported. I personally think this is just a nice feature to have in addition. This issue requires intimate knowledge on how LaTeX works, as well as how it retrieves content from rST. If major changes are required to the existing document structure, it'll be evaluated if it's worth it or not.

Thanks for anyone willing to take on this issue :)