Subclass of java.util.Properties which keeps the order in which properties were loaded,
by delegating to a LinkedHashMap.
Warning: only the java.util.Map interface methods have been
overloaded, so be weary when using java.util.Properties specific methods. (load, save,
getProperty and setProperty are working.) (getProperty had to be explicitly overloaded
The equals() method respects the Map.equals() contract, since the entrySet() method is
delegating to the LinkedHashMap.