GH-1217 add simple instance play time tracking

Not reliable in the face of crashes... but what is?

logic/ftb/LegacyFTBInstance.h

@@ -7,7 +7,7 @@ class LegacyFTBInstance : public LegacyInstance
 	Q_OBJECT
 public:
 	explicit LegacyFTBInstance(SettingsObjectPtr globalSettings, SettingsObjectPtr settings, const QString &rootDir);
-	virtual QString getStatusbarDescription();
 	virtual QString id() const;
 	virtual void copy(const QDir &newDir);
+	virtual QString typeName() const;
 };