- merge changes with development branch (up to rev 23650).

Main changes are: 

  TMath: 

        from David: The following methods now have additional interface working with Iterators as well:  
		MinElement
		MaxElement
		LocMin
		LocMax
		Mean
		GeomMean
		RMS
		BinarySearch
		Sort -> (changed to SortItr)
       	- use now std in binary search algorithm. Old algorithm failed some tests and it is found to be a 
           little bit slower 
       	- do not use std instead in LocMin and LocMax since generic std algorithm is slower on 64 bit arch. 
       	- TMath::PoissonI 
            fix a problem for large values, by using directly the TMath::Poisson implementation
       	- TMath::Landau and TMath::Landau
  		remove duplications by using directly ROOT::Math::landau_pdf and ROOT::Math::landau_cdf
	- TMath::Prob
   		use ROOT::Math::chisquared_cdf_c  (gives also less rounding errors  for small values)
	- TMath::GammaDist
   		use ROOT::Math::gamma_pdf , implementation now returns correct value, 0,  for large values of 
		shape parameter instead of nan
	- TMath::LogNormal:   
  		use ROOT::Math::lognormal_pdf 

	- compile TMath dictionary with -O2 
	- fix a warning in -Wshadow      

        - TMath.h is now  reordered by functionality and alphabetical order

  test: 
	various improvement from David, see http://root.cern.ch/viewcvs?rev=22880&root=root&view=rev	

  - add dictionary for the enumeration used in the Integration class 
  
  - from David: some clean up of Minimizer class (remove typedef definitions)


git-svn-id: http://root.cern.ch/svn/root/trunk@23655 27541ba8-7e3a-0410-8455-c3a389f83636