Might as well do some general cleanup too:
Rename the len attribute of a section to length.
The section, import and export callbacks return 0 on success and anything else
on failure.
Whitespace fixes.
Fix a bunch of copy/paste mistakes in the test script.
Convert the PyObject pointers used inside pepy_parsed into their corresponding
native types and use those. Teach the members array to return them accordingly.
While here might as well add support for signature and machine values.
Also, convert test.py to have shorter output by not using pprint.
