Breaking Change: Making key objects picklable

As mentioned in bob.bio.face!64 (merged) the small hacks made in bob.bio.base to handle pickled stuff is giving more headaches than it should.

So, I decided to make some key objects picklable.

bob/learn/em/test/test_picklability.py

@@ -2,7 +2,6 @@
 # vim: set fileencoding=utf-8 :
 # Tiago de Freitas Pereira <tiago.pereira@idiap.ch>
 
-from bob.pipelines.utils import assert_picklable
 from bob.learn.em import GMMMachine, ISVBase
 import numpy
 import pickle