Lines in code cells get cut when exported to pdf

[duembgen]

There is a cool feature of gitbooks, which is that the full book can be downloaded as a pdf. The automatically generated output looks surprisingly good, and could actually be used as such if at any point a pdf version of this part is desired.

However, if this feature is meant to be used, then all the code blocks should be rewritten such that they fit within the line limit of roughly 100 characters. Unfortunately, automatic line warping is not possible in markdown code blocks, so this would have to be done manually.