with Cartodbfy being invoked by schema triggers. Some
issues with regclass interpretation in tests still remain.
Some issues with slightly different behavior to old version
remain. Some issues with error messages / notification messages
changing a little still remain.
This fix was already present at one point in cartodb/lib/sql
(where the code was copied from) but in a different branch than
the one the code was initially copied from.
The fix depends on plpython language which becomes a new dependency.
NOTE: also makes CDB_TableMetadata triggers still functional
when user quota and varnish invalidation functions are missing
from the database (currently installed by cartodb ruby)
