grok.provides should be renamed

[Thomas Lotze]

The grok.provides directive is used to declare which single interface of those a utility provides it should be registered for. This is different terminology than used with Zope interfaces in general where an object may provide any number of interfaces without regard to registration.

To avoid confusion, the directive should be renamed. There was a discussion on the developers mailing list in October 2008 (starting with <http://mail.zope.org/pipermail/grok-dev/2008-October/006529.html>) which produced no clearly favored new name, but register_for seemed to be a likely candidate.

[Jan Wijbrand Kolman (janwijbrand)]

The discussion stopped at grok.register_for() indeed.

However, grok.provides() is implemented in grokcore.component which is far beyond 1.0. In order to rename this directive, we should do proper deprecation.

I'm postponing this issue until after 1.0.