Adjusting cherrypy WSGI Server import path according to new release

[heronrs]

Fixing cherrypy WSGI import, ref #3195

A couple of questions:

• cherrypy_server_runner has a explicit # pragma: no cover comment. Should I remove it and add a specif test for it ?

• CHANGES.txt doesn`t look like is beeing mainted lately. Should I add an entry to it ?

[heronrs]

Fixing formatting and tox failed test.

[tseaver]

Thanks for the patch!

We don't depend on cherrypy / cheroot at all, which means we cannot test against it, without adding some extra machinery.

Please do update CHANGES.txt: I'll check to see what PRs have been merged since the 1.9 branch forked off, and update it manually.

[tseaver]

This part needs to use cheroot, too. E.g.:

try:
    from cheroot.server import get_ssl_adapter_class
except ImportError:
    from cherrypy.wsgiserver import get_ssl_adapter_class

try:
    from cheroot.ssl.builtin import BuiltinSSLAdapter
except ImportError:
    from cherrypy.wsgiserver.ssl_builtin import BuiltinSSLAdapter

[heronrs]

Thanks @tseaver , I updated what you pointed out 👍

As for CHANGES.txt, I'ḿ not sure which would be the best section to add it. As its not really related to Pyramid itself I don't if it should be considered a Bug Fix. Maybe create a new Backward Compatibilities section ?
What do you think ?

[mmerickel]

A note belongs in features and another in backward incompatibilities mentioning the change in import paths for the cherrypy server runner.

[heronrs]

Guess I need update my fork and resolve the conflicts. Will do it shortly.

[tseaver]

@mmerickel I don't think there is a backward-incompatibility here for Pyramid: we try the cheroot imports first, but fall back to the old cherrypy ones, which means that even users who have an old cherrypy installed will not have to adjust their code (although why they would be installing a new Pyramid and not updating to the lastest cherrypy is beyond me).

[tseaver]

As I noted, I think we can drop this mention: users won't need to adjust their code, which means this is not a backward-incompatibility for Pyramid.

[tseaver]

Can we phrase this more clearly as:

- In `cherrypy_server_runner`, prefer imports from the `cheroot` package over the legacy
  imports from `cherrypy.wsgiserver`.

[mmerickel]

@tseaver you're right of course, I missed that the old imports were preserved as a fallback!