DistSampler: new interface class for sampling a generic distribution
  Possibility to perform unbinned or binned sampling 
  Implementation classes (for example using Unuran) are created  using the plugin manager

  Integration classes: 

  fix a problem with the template method passing a function and fix a bug (function object was not copied)
  Use by default kADAPTIVESINGULAR
  add kLEGENDRE based on GaussLegendreIntegrator 

  DataRange: return -inf,+inf when no range is set 

  mathmore: implement method for calculating function and derivatives for GSLNLSMinimizer


git-svn-id: http://root.cern.ch/svn/root/trunk@33180 27541ba8-7e3a-0410-8455-c3a389f83636