Print the command list as well
Fix typo
Add support for testing missing required parameters

Change the spec so that a key and value setting is separated by a
equals sign instead of space. This allows to have settings that
don't have a correspondent value associated (e.g. --help).

Also change example.py to have a concept of subcommands.
Fix bug caused by optional parameters

Also, add support for tests with *valid* numeric ranges.
Support tests which don't give any value for some setting