and make sure that all TProcessIDs referenced in the Tree are put to the buffer.
This is important in case the buffer is a TMessage to be sent through a TSocket
and the message contains one or more Trees. This improvement is important for PROOF
when the workers send Trees to the master where they are merged.
-in TRefTable::FillBuffer remove my previous change.


git-svn-id: http://root.cern.ch/svn/root/trunk@24224 27541ba8-7e3a-0410-8455-c3a389f83636