first round of renaming to make mostly pep8 compliant

codes/kwant_helper/utils.py

codes/mf.py

codes/model.py

codes/observables.py

codes/params/rparams.py

codes/params/test_params.py

codes/solvers.py

codes/tb/tb.py

codes/tb/test_tb.py

codes/tb/transforms.py

codes/tb/utils.py

codes/test_graphene.py

examples/tEnergyTest.ipynb

examples/testInterface.ipynb

profiling/graphene.py