Significantly improve performance of TTree Proxy by using an 'interface' base...

Significantly improve performance of TTree Proxy by using an 'interface' base class instead of CINT to allow support optional within the user's script. (This brings TTree Proxy from being 50% slower than the optimal case (for h1analysis) to being within the measurement incertainty of this optimal).


git-svn-id: http://root.cern.ch/svn/root/trunk@27127 27541ba8-7e3a-0410-8455-c3a389f83636