py-waitress: updated to 1.2.0

1.2.0:
No changes since the last beta release. Enjoy Waitress!

1.2.0b3:
Bugfixes
- Modified clear_untrusted_proxy_headers to be usable without a
  trusted_proxy.

- Modified trusted_proxy_count to error when used without a
  trusted_proxy.

1.2.0b2:
Bugfixes
- Fixed logic to no longer warn on writes where the output is required to have
  a body but there may not be any data to be written. Solves issue posted on
  the Pylons Project mailing list with 1.2.0b1.

1.2.0b1:
Happy New Year!

Features
- Setting the trusted_proxy setting to '*' (wildcard) will allow all
  upstreams to be considered trusted proxies, thereby allowing services behind
  Cloudflare/ELBs to function correctly whereby there may not be a singular IP
  address that requests are received from.

  Using this setting is potentially dangerous if your server is also available
  from anywhere on the internet, and further protections should be used to lock
  down access to Waitress.

- Waitress has increased its support of the X-Forwarded-* headers and includes
  Forwarded (RFC7239) support. This may be used to allow proxy servers to
  influence the WSGI environment.

  This also provides a new security feature when using Waitress behind a proxy
  in that it is possible to remove untrusted proxy headers thereby making sure
  that downstream WSGI applications don't accidentally use those proxy headers
  to make security decisions.

  The documentation has more information, see the following new arguments:

  - trusted_proxy_count
  - trusted_proxy_headers
  - clear_untrusted_proxy_headers
  - log_untrusted_proxy_headers (useful for debugging)

  Be aware that the defaults for these are currently backwards compatible with
  older versions of Waitress, this will change in a future release of waitress.
  If you expect to need this behaviour please explicitly set these variables in
  your configuration, or pin this version of waitress.

  Documentation:
  https://docs.pylonsproject.org/projects/waitress/en/latest/reverse-proxy.html

- Waitress can now accept a list of sockets that are already pre-bound rather
  than creating its own to allow for socket activation. Support for init
  systems/other systems that create said activated sockets is not included.

- Server header can be omitted by specifying ident=None or ident=''.

Bugfixes
- Waitress will no longer send Transfer-Encoding or Content-Length for 1xx,
  204, or 304 responses, and will completely ignore any message body sent by
  the WSGI application, making sure to follow the HTTP standard.

Compatibility
- Waitress has now "vendored" asyncore into itself as waitress.wasyncore.
  This is to cope with the eventuality that asyncore will be removed from
  the Python standard library in 3.8 or so.

Documentation
- Bring in documentation of paste.translogger from Pyramid. Reorganize and
  clean up documentation.


(adam)