BasePotential now inherits from BaseSignal which is the base class for
entities representing any recorded signals. As a result some methods that used
to belong to BasePotential now belong to BaseSignal so that for instance
entities like Pressure (which is not a Potential) can get access to
methods like CalculateSlope. You can now plot a pressure, reference signal
and unemap Vrms waveform in PressureAnalysis. You can time align signals
and resample. Next will be to make resampling permanent (save it to
Pressure.Resampled data) and have a flag to tell whether the figure is
dealing with original or resampled data.