'spec' Structure: Spectrum, Acquisition, and Processing Information
'par' Structure: User Instructions for FitSpec
'd1',...,'dn' Sub-Structures: Lineshape Information
'fit' Structure: Output of FitSpec
'fit0' Structure: Initial Fits and Controlling Fit Variables
'shapes0' Cell: User Specified Lineshapes
'shapes' Cell: Recyling Lineshapes for Similar Spectra