1.6.0 - we now have our own version of `@autoclass`

• Copied the relevant contents from autoclass so as to get rid of the dependency. Since we are in a pyfields context there were many things that could be dropped and remaining code could be easily copied over. Also took this opportunity to replace the dict view with a to_dict/from_dict pair of methods, this seems less intrusive in the class design. Finally the parameter names have been simplified, see API reference for details. Fixes #79

See documentation page for details.