Main changes of version 1.3, versus version 1.2:

o Added type aliases
o Added real/float type
o Added traceability, see option -tracing for details
o Various minor bugs



git-svn-id: https://svn.onera.fr/Prelude/Prelude/prelude-1.3@650 49f62630-d767-4ccd-930e-b3f5589f52e1