Merge branch 'master' of https://github.com/hyperspy/hyperspy into chi_squared

Conflicts:
	hyperspy/model.py
changed tests to comply with the chisq calculations when no variance is given
Automatic style corrections courtesy of autopep8
added stop, arguments for the fitter
Automatic style corrections courtesy of autopep8
added "active" parameter attribute passing
added missing channel switches for variance
Automatic style corrections courtesy of autopep8
Merge branch 'model_as_dict' into parafit
Merge branch 'chi_squared' into parafit

Conflicts:
	hyperspy/model.py
Automatic style corrections courtesy of autopep8