Remove use of data member fOnFileClass as much as possible (improve thread safety).  Improve const-correctness


git-svn-id: https://root.cern.ch/svn/root/branches/v5-34-00-patches@49000 27541ba8-7e3a-0410-8455-c3a389f83636
Implement convertion to any type of numeric STL in the collection streamer


git-svn-id: https://root.cern.ch/svn/root/branches/v5-34-00-patches@49001 27541ba8-7e3a-0410-8455-c3a389f83636