Extract: docstrings lie

[akx]

• messages.extract():
  • Docs say: This function returns tuples of the form (lineno, message, comments).
  • Yields 4-tuples (lineno, messages, comments, context)
• messages.extract_from_file():
  • Docs say: This function returns a list of tuples of the form (lineno, funcname, message).
  • Returns a list of 4-tuples (lineno, messages, comments, context) (from extract)
• messages.check_and_call_extract_file():
  • Does not document what it returns
  • Yields 5-tuples (filename, lineno, messages, comments, context)
• messages.extract_from_dir():
  • Docs say: This function generates tuples of the form (filename, lineno, message, comments, context).
  • Actually does exactly that!

[ztane]

+1 I had to actually look into source code on how to write an extractor that properly returns context and plurals. Fix the pocoo docs as well.