WiggleZ clean, P0 being tested
Bring Monte Python in adequation with CLASS 2.0

Since the function names changed in classy, the Class wrapper, to have
a more coherent pattern, the code was not working anymore.
CLASS fail is now verbose

This to prevent the previous version, when using alongside CLASS
v2.0.0. The code was simply terminated without any error message. This
should no longer be the case.
Work with Class v2.0.0. and classy wrapper

* devel:
  CLASS fail is now verbose
  Bring Monte Python in adequation with CLASS 2.0
  WiggleZ clean, P0 being tested