Adding current versions of Detect_Ringdown_delta_f.py and Detect_Ringdown_derivada.py
Code change to allow easy parameterization of the time and frequency variation that define the normality range
Adding initial version of Sub_GeraGrafRingdown.vba. This version creates the dict, the severity groups, and the graphic. But the graphic is not totally formated yet.
Merge branch 'master' of https://github.com/RomuloMenezes/DetectRingdown