This Comparator implements the standard java.util.Comparator interface. The intended use is to group MetaData
elements based on either: (1) The ordinal value in the groupsorting.properties file (see documentation in that file
for how this is accomplished. Any group(s) not represented in that file will be displayed last if more than one
group they will all be displayed last in alpha order. (2) If the groupsorting.properties doesn't exist or can't be
loaded, the value of the *.grouping key (using the standard string compare).
This effectively sorts the attribute and style elements into groups for display by a GUI. Fine grain ordering of the
groups can be accomplished using the groupsorting.properties file.
Documented by William Seyler