Javadoc
INTERNAL:
Call this method if the uow will no longer used for comitting transactions:
all the changes sets will be dereferenced, and (optionally) the cache cleared.
If the uow is not released, but rather kept around for ValueHolders, then identity maps shouldn't be cleared:
the parameter value should be 'false'. The lifecycle set to Birth so that uow ValueHolder still could be used.
Alternatively, if called from release method then everything should go and therefore parameter value should be 'true'.
In this case lifecycle won't change - uow.release (optionally) calls this method when it (uow) is already dead.
The reason for calling this method from release is to free maximum memory right away:
the uow might still be referenced by objects using UOWValueHolders (though they shouldn't be around
they still might).