activity

Implemented activity function. No documentation yet.
activity documentation

Added documentation to activity function.
decay started

Started implementation of the decay function.
decay finished

Implemented decay function as well as finished the documentation.
removed weights in calibration

Removed the fallacious weights in the calibration function. The weights
were being used for the energies, but intended for the channels. That's
not really easy to do however, since the channels are on the x-axis.
residuals in peaklocate

Added pearson residuals to peaklocate output.