* Extract WSGIEnvironment in wsgiref.types
* Change value type of WSGIEnvironment to Any
Per PEP 3333, a WSGI environment can contain anything, not just strings.
- 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.
This type is something core to Python and is useful when typing web applications,
but doesn't actually exist in the stdlib anywhere. I put this in wsgiref, but I am
open to suggestions as for a better place.
(Original PR by @rowillia.)
