OS Statistics Plots

Adds plots for OS statistics.

 On branch master

 Changes to be committed:
	modified:   Ltt/Display.pm
	modified:   Ltt/Plotting.pm
	modified:   Ltt/Upload.pm
	modified:   json/constants.json
	new file:   json/hbar_os_family_stats_configs.json
	new file:   json/hbar_os_stats_configs.json
	modified:   json/json_files_record.json
	modified:   json/os_abbr_key.json
	modified:   ltt-rankings.pl
	modified:   ltt-rankings.txt