BUGFIXed cascade transactions.

Multisteps transactions were unpredictable and would fail miserably.
Impossible to know why. When executing exactly what was stored into proc calls and bypass procs: it works.
Tried with OpenStruct and broke a little isolation to let know the cleaner how to deal with.
It is easy : openstruct has an dao object stored in as well as arguments et method to call ...
Added additional tests to ensure cascade transactions / deletions are handled properly.

It's now GREEN. OKI ?
bump to version 0.2.5