Added LaTeX package and BibLaTeX setting

* Added LaTeX package xfrac for better text formatting options,
  e.g. "\sfrac{1}{2}" can display one half as a pretty text symbol

* With the BibLaTeX setting "maxnames=99" there are now displayed
  more than just two authors of an reference entry in the
  bibliography
Added two reference entries to the bibliography
Added "CAx" section and content for chapter 2