From Brian Bockelman: Add more clusters to the TTreeCache buffer until fBufferMinSize is hit to avoid severely underfilled buffer when a low number of branches is selected/used.
From Brian Bockelman:
Add more clusters to the TTreeCache buffer until fBufferMinSize is hit to avoid severely underfilled buffer when
a low number of branches is selected/used.


git-svn-id: ecbadac9c76e8cf640a0bca86f6bd796c98521e3@37955 27541ba8-7e3a-0410-8455-c3a389f83636

dawehner/root,dawehner/root,dawehner/root,dawehner/root,dawehner/root,dawehner/root,dawehner/root,dawehner/root