Usability: new cmdline options, new pythran interface.py, TestFromDir() class helper, and a few bugfixes

Multiples things here. 

* The most important changes is a new interface around ToolChain(), the unittests are updated and I expect some failures, not because of regression but because some tests where not executed previously or the output was not compared. This is the case now thanks to a refactoring.

* A "-v" option is now proposed, it display the command line used for the cxx compiler (if any) and the path/name of the generated file.

* pythran accepts also now .cpp files on the command line, allowing two-stage compilation (first with -E to generate the .cpp).

* Also a bug fix in pythonic++ (try to run rosetta and you'll have an infinite recursion with gcc 4.8).

* "python setup.py test" starts now with a "dummy" compilation, just to test the flow/the environment.