Files will be rotated once a day or if they grow to 100 MB up to 7 stages.

 - add new log files to .gitignore
 - refine documentation and install scripts
 - refine log level of "Starting/stopping execution..." to become visible
   in rotated logs
 - minor other log refinements

 - add detailed installation instructions
 - refine appendix
 - various smaller refinements and style changes

 - Switch is only used once in the code and easily substituted by some
   if-elsif-else clauses... thus remove it.
 - Add usage information to all other packages in the documentation
   where it was missing.