[repo] move repo stats to Service (closes #2951067)
We currently add a new method on repo that anyone can call. Call service allows
to reach the same result with:
* Restricted access to manager only (thanks to selection on services),
* Less unrelated code on the repo.
* No need to fetch a reference to a repo object from client side.
`req._cnx.repo` is not an API and config.repository() is on its way out.
The old way to access this information (repo.stats()) is deprecated.
What's new in CubicWeb 3.17?
============================
New functionalities
--------------------
* add a command to compare db schema and file system schema
(see `#464991 <http://www.cubicweb.org/464991>`_)
* Add CubicWebRequestBase.content with the content of the HTTP request (see #2742453)
(see `#2742453 <http://www.cubicweb.org/2742453>`_)
* Add directive bookmark to ReST rendering
(see `#2545595 <http://www.cubicweb.org/ticket/2545595>`_)
* Allow user defined final type
(see `#124342 <https://www.logilab.org/ticket/124342>`_)
API changes
-----------
* drop typed_eid() in favour of int() (see `#2742462 <http://www.cubicweb.org/2742462>`_)
* The SIOC views and adapters have been removed from CubicWeb and moved to the
`sioc` cube.
* The web page embedding views and adapters have been removed from CubicWeb and
moved to the `embed` cube.
* The email sending views and controllers have been removed from CubicWeb and
moved to the `massmailing` cube.
* ``RenderAndSendNotificationView`` is deprecated in favor of
``ActualNotificationOp`` the new operation use the more efficient *data*
idiom.
* Looping task can now have a interval <= ``0``. Negative interval disable the
looping task entirely.
* We now serve html instead of xhtml.
(see `#2065651 <http://www.cubicweb.org/ticket/2065651>`_)
Deprecation
---------------------
* ``ldapuser`` have been deprecated. It'll be fully dropped in the next
version. If you are still using ldapuser switch to ``ldapfeed`` **NOW**!
* ``hijack_user`` have been deprecated. It will be dropped soon.
Deprecated Code Drops
----------------------
* The progress views and adapters have been removed from CubicWeb. These
classes were deprecated since 3.14.0. They are still available in the
`iprogress` cube.
* API deprecated since 3.7 have been dropped.