UTM builtin support

This branch adds UTM support for geoCoordinates to Geospatial.js by implementing UTMtoGC with the math for inverse transverse Mercator projection based on S. Dutch's, UWGB, javascript code (https://www.uwgb.edu/dutchs/UsefulData/ConvertUTMNoOZ.HTM) and then using the existing GDtoGC function to compute the desired geocentric WGS84 coordinates.