Merge branch 'wakepotential'

collective_effects/__init__.py

collective_effects/impedance_model.py

collective_effects/resistive_wall.py

collective_effects/resonator.py

collective_effects/tapers.py

collective_effects/utilities.py

collective_effects/wakefield.py

tracking/__init__.py

tracking/element.py

tracking/monitors/__init__.py

tracking/monitors/monitors.py

tracking/monitors/plotting.py

tracking/synchrotron.py

tracking/wakepotential.py