[server] add a db-namespace option in source definition (closes #1631339)
"namespace" is preferred to the postgresql term "schema" to try and
avoid confusion with cubicweb's schema.
cubicweb now depends on logilab-database >= 1.13.0
Schema of the data
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First take a look at the data schema_ then try to remember that you are browsing
through a heap of data by applying stylesheets to the results of queries. This
site is not a content management system with items placed in folders. It is an
interface to a database which applies a view to retreived data.
.. _schema: schema