[Framework-Team] RFC: Deprecation

[Jens W. Klein]

I committed myself to dive a bit into the deprecation-topic. This is a 
small update of work in progress.

Earlier in Plone we had ugly-nice deprecation-warnings on zope startup. 
Now, even when in buildout plone.recipe.zope2instance setting 
"deprecation-warnings = on" is set this has no effect anymore.

The silent dead of this feature is because a) Python 2.7 switched off 
deprecation warnings by default[1] and b) Zope had a bug to overwrite 
this (which I fixed meanwhile and Tres merged it) [2].

[1] https://docs.python.org/2/using/cmdline.html#cmdoption-W
[2] https://github.com/zopefoundation/Zope/pull/24

I also started to add a chapter about deprecation to the coredev docs on 
a branch [3].

[3] 
https://github.com/plone/buildout.coredev/blob/deprecation-done-right/docs/deprecation.rst

Please take some minutes and read at least the Use-Cases and comment on 
them. If they are fine, I'd prepare code-examples how to achieve the 
goals from the use-cases.

regards Jens
-- 
Klein & Partner KG, member of BlueDynamics Alliance