[validation api] properly use yams 0.36 validation error api and update message catalog. Follows bbe0d6985e59
the creation of the `translate` method in the 23a10f049447 yams commit.
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