[testlib] move repo and related attribute back on Instance instead of Class
The repo and cnx was hold by the TestCase class to work as a cache and avoid
recreation of the repo from scratch of each test. However since bad26a22fe29 the
caching is done by the DatabaseHandler object and it is not necessary have a
second layer of cache on the TestCase itself.
We move the repo and cnx attribute back on the TestCase instance itself and make
several class methods instance methods again.
This will helps to change dbapi access in test from dbapi to repoapi.
related to #2503918
About this site
===============
This web application is based on the CubicWeb knowledge management system
from Logilab_. CubicWeb is made of an object database and a web
framework. It allows to develop an application by defining a set of
entities and their relationships, plus a set of views that present the
data selected from the object database using a specific query language.
This application has a precise schema_ and can be considered an
example of a semantic web database, as it can export the data to XML
and others formats and is not limited to publishing HTML.
Supported formats: |microformats|_ - JSON_ - |rss|_ - |dublincore|_
.. |microformats| image:: /data/microformats-button.png
.. _microformats: http://microformats.org
.. _JSON: http://www.json.org/
.. |rss| image:: /data/rss-button.png
.. _rss: http://www.rssboard.org
.. |dublincore| image:: /data/dublincore-button.png
.. _dublincore: http://dublincore.org
.. _Logilab: http://www.logilab.fr/
.. _schema: schema