Class for regularized model using general purpose optimization interface
penaltypenalty used (e.g., "lasso")
parametersdata.frame with all parameter estimates
fitsdata.frame with all fit results
parameterLabelscharacter vector with names of all parameters
weightsvector with weights given to each of the parameters in the penalty
regularizedcharacter vector with names of regularized parameters
internalOptimizationlist of elements used internally
inputArgumentslist with elements passed by the user to the general purpose optimizer