Experimental changes to edges to make them more adaptive.
Exerpiments with adaptive bedges
Fixed experimental change bug in bedges.
Added new parts coding that is slightly faster and uses less memory.

- Also some experimental changes in bedges.py.
Testing new parts threshold (log ratio against homogenized parts).
Added adaptive bkg for edges
Support for coding strides in code_parts.pyx.
Changed the way you specify collapsing features.
Added support for rotation spreading.
Added n_init (restarting EM) in BernoulliMixture.
Added support to load NORB files.

- So far only the small dataset, but easily adaptable.
Merge branch 'dev-threshold-change'

Conflicts:
	amitgroup/features/bedges.py
Merge branch 'master' of github.com:amitgroup/amitgroup

Conflicts:
	amitgroup/__init__.py
	amitgroup/features/bedges.py