[webrequest] introduce an alternative implementation using the repoapi DBAPI specific parts of ``CubicWebRequestBase`` are extracted in a ``DBAPICubicWebRequestBase`` decicated class and a new ``ConnectionCubicWebRequestBase`` is introduced that provide the same services but using a repoapi.ClientConnection as data source. For now the ``DBAPICubicWebRequestBase`` is still used by default.

.. winclude:: search_sample_queries

You can as well type complex queries using the RQL_ query language, 
used every where to build dynamic pages of this site.

You can use one of the following prefixes to specify which kind of search you
want: 

* `rql` : RQL query
* `text` : full text search

.. _RQL: doc/tut_rql