[entity] more tweaks for entity attribute cache handling on cw_set/cw_create to fix test regression
* when an attribute is listed in dont-cache-attrs, purge any previous value
* test value is actually modified in EditedEntity.__setitem__ before adding
attribute to dont-cache-attrs
Schema of the data
------------------
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