templatekw: mark _showlist() as deprecated (API) .. api:: ``templatekw._showlist()`` is deprecated in favor of ``templateutil._showcompatlist()``, which takes ``context`` in place of ``templ``.

templater: drop 'templ' from resources dict Partially resolves cycle, templ -> context -> templ. This will make it easier to replace the resources dict with new immutable resource mapper interface.