Merge remote-tracking branch 'dev/NIFTy_5' into sebastian_review

README.md

docs/source/code.rst

docs/source/conf.py

docs/source/ift.rst

docs/source/index.rst

docs/source/installation.rst

nifty5/domains/domain.py

nifty5/fft.py

nifty5/library/smooth_linear_amplitude.py

nifty5/linearization.py

nifty5/minimization/energy.py

nifty5/minimization/iteration_controllers.py

nifty5/minimization/line_search.py

nifty5/minimization/minimizer.py

nifty5/operators/block_diagonal_operator.py

nifty5/operators/energy_operators.py

nifty5/operators/operator.py

nifty5/operators/value_inserter.py

nifty5/probing.py

nifty5/sugar.py