Changes in Version 0.1-1

  o New "psychotools" package containing all 'base' infrastructure
    previously contained in "psychotree". This is in order to provide
    both methods and data that can be reused by "psychotree" and
    the new package "psychomix" (as well as potentially further packages).
    
  o Classes: "paircomp" and associated methods.
  
  o Models: btReg.fit() and RaschModel.fit() and associated methods.
  
  o Data: Firstnames, GermanParties2009, Soundquality (previoulsy in
    psychotree) and VerbalAggression (new data, contained in other
    formatting in difR/verbal and lme4/VerbAgg).
