sicegar 0.3.0

• Added functionality so that the lower asymptote (h0) can be estimated freely, instead of forced to be zero. To implement, toggle use_h0 = TRUE in fitAndCategorize() and figureModelCurves().
• Set default value of threshold_t0_max_int to 1E10.
• Fixed typo in object assignment of decisionList$test.sm_tmax_IntensityRatio.
• Fixed typo so that now the asymptote ratio (parameterDF$finalAsymptoteIntensityRatio_Estimate) is also unnormalized, along with all other parameters.
• Updated ggplot functions to have current syntax.
• Edited grammar and spelling throughout.