Object thrown by GC from weak cache are linked into forgottenObjectList
list and notifications are send to servers at the transaction
commit time. This is done because clearing weak reference by GC
is not synchronized with invocation of finalize() method. So there is
no warrenty that in the moment between object is removed from weak cache
and ionvocation of finilize method, the object with the same identifier
will not be retirieved from the server. Delayed strategy of sending
forget message together with checking object for presence in the cache
before sending foget message to the server makes sending of wrong
forgot message not possible.
OId's of Object that were "forgotten" are collected and handed to
Storage.forgetObjects