We test here that all ../faust2* work correctly:

- testfailure: tests that all faust2xxx scripts correctly fails and report error when there 
  is and error either in the faust code or in the generated c++ code. For that purpose we
  use 'badfaust.dsp' and 'badcpp.dsp' (correct faust code but bad generate c++ code).

- testsuccess: tests that all faust2xxx scripts correctly compile 'good.dsp'



