Implemented configuration frame work

Added reading and writing machinery's configuration file.
The file machinery_config.rb contains the default values
used when no configuration file is present.

We should not do parsing here, but check if the type of the given value matches the type already stored. This way we provide type safety of config values, so users of the API can't accidentally set wrongly typed values with unknown side effects. But we should expect users of the API to use native types.