+ 10 Dec 2009 Kevin Rosenberg <kevin@rosenberg.net>
+ Large patch from Thijs Oppermann <thijso+clsql@gmail.com> to add
+ support for normalized view classes. When having view class that
+ inherit from others, CLSQL by default builds tab all the columns
+ from the parent in the child. This patch is meant to normali so
+ that a join is done on the primary keys of the concerned tables to
+ get a set.
+