#16 Various OQL trigger bugs

[Francois Dechelle]

Defining OQL triggers show several bugs:

- bug 1: OQL trigger update_before crashes if updating same object
- bug 2: OQL trigger update_after shows same values
- bug 3: OQL trigger load_before crashes
- bug 4: OQL trigger load_after prints bizarre message

ODL schema and testcases are commited in source tree: tests/bugs/oql-triggers