Operating System Statistics

Adds OS family statistics.

 On branch master

 Changes to be committed:
	modified:   Ltt/Display.pm
	modified:   Ltt/Statistics.pm
	modified:   json/constants.json
	modified:   ltt-rankings.pl
	modified:   ltt-rankings.txt
Operating Systems Statistics

Fixes bug which did not count all operating system
occurrences.

 On branch master

 Changes to be committed:
	modified:   json/constants.json
	modified:   ltt-rankings.pl
	modified:   ltt-rankings.txt