o) opt in ObjectProxy.h: skip creating of temporary TClassRef
 o) TPython::Exec now returns kFALSE on failure
 o) TPySelector now takes a python module, so that that file is
      looked up through PYTHONPATH, and it searches for the
      TPySelector derived class to instantiate and use


git-svn-id: http://root.cern.ch/svn/root/trunk@22759 27541ba8-7e3a-0410-8455-c3a389f83636