Java utility which provides methods to determine the sunrise and sunset time of a given location, or if it is currently day or night at a given location.
Also provides methods to convert between Greogrian and Julian dates.
The formulas used by this class are from the Wikipedia articles on [Julian Day] (http://en.wikipedia.org/wiki/Julian_day) and [Sunrise Equation] (http://en.wikipedia.org/wiki/Sunrise_equation).