Fixed build warnings and undo changes

- Build problems:
    - Qt 5.13 obsoleted some calls that were used in our Qt library.
    - The PhilipsHueLight and PhilipsHueBridge classes did not use the private logger class
- Undo changes:
    - In Commit e6c2e7e, I made changes that were not covered. An apology goes to @b1rdhous3

Signed-off-by: Paulchen-Panther <Paulchen-Panter@protonmail.com>

include/commandline/Option.h

@@ -15,13 +15,13 @@ class Option: public QCommandLineOption
 public:
 	Option(const QString &name,
 		  const QString &description = QString(),
-		  const QString &valueName = QString::null,
+		  const QString &valueName = QString(),
 		  const QString &defaultValue = QString()
 	);
 
 	Option(const QStringList &names,
 		   const QString &description = QString(),
-		   const QString &valueName = QString::null,
+		   const QString &valueName = QString(),
 		   const QString &defaultValue = QString()
 	);