It was broken for South/West values.
Added additional tests for maximum long/lat values.
Requires field testing to make sure values are correct on the telemetry
display.
The existing implementation that was ported over was trying to work with
different values. By writing a unit test for the code that stores
values in GPS_coord it was possible to have known values which could
then also be used to write a unit test for the HoTT telemetry which
finally enabled production code to be written.
Hopefully it will work, unable to test further since my GPS unit is
playing up.
