Various code householding

- Adjust javadoc
- Remove unused PlayerAuth constructor
- Replace legacy Settings with NewSetting calls
- Add process service to all (a)sync processes
- Change IP manager to only cache the calls to the VeryGames API

src/main/java/fr/xephi/authme/command/CommandUtils.java

@@ -8,6 +8,9 @@ import java.util.List;
 
 public final class CommandUtils {
 
+    private CommandUtils() {
+    }
+
     public static int getMinNumberOfArguments(CommandDescription command) {
         int mandatoryArguments = 0;
         for (CommandArgumentDescription argument : command.getArguments()) {