Allow UTM Zone to use hemispheric designator or latitude band designator

[mccoy1]

The UTM Zone letter designator can be two different formats. One is the latitude band designator (which is implemented in this library). The other is the hemispheric designator, an N (north) or S (south). Both are valid UTM and both are in present use. When converting to UTM, it would be helpful to be able to choose which method to use.

Example. Latitude: 46.475823 Longitude: -14.250822

UTM (with latitude band): 28T 557511mE 5147189mN UTM (with hemisphere): 28N 557511mE 5147189mN

Both conversions can be calculated here: http://www.rcn.montana.edu/resources/converter.aspx

https://en.wikipedia.org/wiki/Universal_Transverse_Mercator_coordinate_system#Notation