relax SVN archive

Split the read_columnar_results() method into version specific methods.

Wrote a method for determining which relax version the results file belongs to.

Split off all the model-free results files methods into their own module.

Renamed the main model-free module.

The original module was specific_fns.model_free.model_free whereas the new is
specific_fns.model_free.main.

Numeric to numpy conversion.

Added a missing import.

Added an empty package __init__ module.

Added a directory for unit tests of the model-free specific code.

Added an empty package __init__ module.

Directory rename.