[selectors] match_kwargs and match_form_params selectors both accept a new `once_is_enough` argument (closes #1990438)
also fix docstring of match_exception and references to selectors in the book.
.. _Part2:
----------------------
Repository development
----------------------
This part is about developing applications with the *CubicWeb*
framework. It is not concerned with the web system, which is a
separate layer and has its own whole chapter.
.. toctree::
:maxdepth: 2
:numbered:
cubes/index
vreg.rst
datamodel/index
entityclasses/index
devcore/index
repo/index
testing.rst
migration.rst
profiling.rst