Added PAX South to program, added small features

-Changed version to 1.3.0
-Added data usage counter -- byte count stored in long, displayed in #.##MB format on Status GUI
-Added PAX South icon to resources
-Added PAX South option to Setup GUI
-Added PAX South compatibility to Browser.getWebsiteLink(), PAXChecker.getIconName(), and Setup.getIndexOfEvent()
-Appended PAXCHECKER_ to all Preference names to not conflict with other Java programs using Preferences API
-Small code optimization recommended by Netbeans (redundancy in SettingsHandler, setting object to final, etc)