SCEPTAR O(1)

Taggable version now supporting the full SCEPTAR simulation as its own set of plots.  Fits to these simulations are good to a colloquial first order - there are a number of corrections applied to force them to good health:

- The fit parameter governing the high Q asymptote is fixed to 0.8 to conform to experiment; simulations fail to capture this behaviour.

- Positron efficiency is fixed to a minimum of 0.065%, the simulated efficiency of SCEPTAR for the annihilation photopeak.

- All SCEPTAR efficiencies are fixed to a minimum of 0; in some cases, the fit shows a nonphysical negative excursion at low electron Q and high thresholds.

- All efficiencies are fixed to 0 for Q <= 100keV

- Some parameters in some fits failed to converge; values were used as is, but these correspond to initial guesses and not converged fits.