Fix caption package warning:

This fixes the following warning message: “Package caption Warning:
Unsupported document class (or package) detected, usage of the
caption package is not recommended.” As far as I can tell, this does
not change the rendered output of the document.
Remove superfluous \begingroup...\endgroup.
Fix erroneous “.0.” in headings in appendices.
Remove listingsutf8 package.
Editorial amendments.