MaTransaction memory hog

[Chris Muller]

> Apparently, the only problem which could occur, that when you in the
> middle of finalization, cleaning the dictionaries from
> obsolete entries, being interrupted with higher priority process which
> by touching the domain objects and triggers modifications to these
> dictionaries (like adding new oid's & dirty objects).

Ok, that process runs at #userInterruptPriority (50).  Unless the
application is forking a process above that, it won't be able to
agitate any proxies during finalization.

 - Chris