Better rounding for decimal degrees to degrees, minutes, seconds

When formatting latitudes and longitudes using Decimal degrees, the rounding produces some odd output when the data stores recurring values.

For example, the location of 1 degree and 20 minutes will be stored as 1.333333333333

But when it's converted back to to degrees minutes seconds for display, it will show as 1 degree 19 minutes 60 seconds (which isn't really a nice way write a coordinate, much like it's not correct to write 11:60 instead of 12:00)

Steps to reproduce.

1. Add a geofield to a node
2. Set the output format for the field to "Decimal degrees"
3. Create a node and set the geofield values to latitude 1.333333333333 and longitude 179.999999999999. (using 12 decimal places because that is the database precision)

Expected:
Latitude: 1° 20' 0" N
Longitude: 180° 0' 0" E

Actual:
Latitude: 1° 19' 60" N
Longitude: 180° 0' 0" E

Note:
The 179.999999999999 actually gets rounded to 180 when it's stored in the DB.
if we use one less decimal precision on the input, we actually see 179° 59' 60" E on the output.