From Philippe:

This patch comments the fact after TTree::CloneTree and until the original is deleted, the addresses of the original
are passed on to all the clones.  Also the addresses of the clones are reset when the original is deleted.

This patch also simplify the implementation of TChain::Merge to take advantage of the new TTree::CloneTree feature.


git-svn-id: http://root.cern.ch/svn/root/trunk@6838 27541ba8-7e3a-0410-8455-c3a389f83636