Improved Build Process and More Accurate Log Information

The build process now produces two more artifacts: an archive with the documentation and a frozen requirements file.
This should help to better document and distribute the package.

The log files now contain the version information of more dependencies.
Also, the log information string is not entirely re-created on forks, but only the CPU affinity is updated.
This means that the correct numbers of physical and logical CPUs are now logged in parallel builds.