This prevent increasing the memory usage due to huge workflow history.

distribution check: added a few tests

- Raise early
- Also add sanity checks and correct output errors.
- This was outputting bad error message in some cases, making debugging
impossible.

- Clearly define the imports
- Refactor specific mockup

Fix additional_buildout_parametr_list to read
additional_buildout_parameter_list

Conflicts:
	slapos/format.py