Add http-fast-listen option for waitress

[tschorr]

s. #71 (and also zopefoundation/Zope#416).

waitress.serve() accepts a list of (prebound) sockets, https://waitress.readthedocs.io/en/latest/arguments.html.

Suggestion is to bind a socket before loading the application and to use a custom server_factory to make this work with PasteDeploy. This could also be done in https://github.com/zopefoundation/Zope, but plone.recipe.zope2instance is already relying on waitress anyway (Zope doesn't really seem to depend on waitress even though it is currently required it in it's setup.py).

[mister-roboto]

@tschorr thanks for creating this Pull Request and help improve Plone!

To ensure that these changes do not break other parts of Plone, the Plone test suite matrix needs to pass.

Whenever you feel that the pull request is ready to be tested, either start all jenkins jobs pull requests by yourself, or simply add a comment in this pull request stating:

@jenkins-plone-org please run jobs

With this simple comment all the jobs will be started automatically.

Happy hacking!

[tschorr]

@jenkins-plone-org please run jobs

[tschorr]

@jenkins-plone-org please run jobs

[tschorr]

@jenkins-plone-org please run jobs

[jensens]

So, I am not an expert exactly on WSGI and waitress, but it looks ok. Was it tested on Windows?

[icemac]

Hm, there are broken tests, I'd like to review after they are fixed.

[tschorr]

There are broken doctests after merging master. I'm about to fix them. Don't merge

[tschorr]

@jenkins-plone-org please run jobs

[tschorr]

@icemac Travis tests are green now and the one failing Robot Test on Jenkins looks unrelated. Feel free to review.

@jensens I currently don't have an opportunity to test this on Windows

[icemac]

LGTM. I only read the code, I did not try it out.

I got confused a bit by some function names, maybe they could be changed for clarity.

[tschorr]

@icemac I'm basically following https://pastedeploy.readthedocs.io/en/latest/#paste-server-factory. I opted for import waitress and waitress.serve to avaoid the ambiguity.

[icemac]

@jenkins-plone-org please run jobs

[tschorr]

Again the one failing robot test looks unrelated.

[jensens]

Indeed, I merge this one now.