Give it enough information to determine that addinfourl
is iterable and that iteration and read methods return bytes.
Modeled after what is in stdlib/3/urllib/response.pyi after confirming
by looking at Python 2.7 stdlib code.
- Updates documentation related to previously required comment headers.
- Removes all comment headers from stubs
- Occasionally included a header for stubs that were noted to be incomplete or contained todo's.
