- It is now possible to define the precision of the default histogram created

  by `TTree::Draw`. Three new parameter dre available in `$ROOTSYS/etcsystem.rootrc`

   Hist.Precision.1D:           float
   Hist.Precision.2D:           float
   Hist.Precision.3D:           float

  the fault values are `float`. They can be set to `double`.