sphinx.environment: PEP8 cleanup.
Fix URL in docu for opensearch.
Changing the default role document-locally with the docutils ".. default-role::"
directive is now supported.
clean up default-role usage in CHANGES
Clean up reference resolution a bit; factor out :doc: and citations into their
own methods.
Added the `any` role that can be used to find a cross-reference of
*any* type in *any* domain.  Custom domains should implement the new
`~Domain.resolve_any_xref` method to make this work properly.

--HG--
extra : amend_source : 93228213f22c99bf082f17d46a388d2ab84908d0
Use "any" role in changelog.
Fix duplication of bugfixes between 1.2.x and 1.3 in changelog.
make :any: role work with intersphinx!
Add tests for "any" role and default-role setting. Fix some minor bugs with "any".