refresh time for all devices + schema fixes (#305)

* refresh for all :-)
remove dups

* - integrate refresh leds for all devices
- fix schemas for led devices

* add minimum for rewrite time

* rewriteTime: add missing info in config examples

include/leddevice/LedDevice.h

@@ -68,6 +68,7 @@ protected:
 	/// @return Zero on success else negative
 	///
 	virtual int write(const std::vector<ColorRgb>& ledValues) = 0;
+	virtual bool init(const QJsonObject &deviceConfig);
 
 	/// The common Logger instance for all LedDevices
 	Logger * _log;
@@ -86,8 +87,9 @@ protected:
 
 	/// Timer object which makes sure that led data is written at a minimum rate
 	/// e.g. Adalight device will switch off when it does not receive data at least every 15 seconds
-	QTimer     _refresh_timer;
-
+	QTimer        _refresh_timer;
+	unsigned int _refresh_timer_interval;
+	
 protected slots:
 	/// Write the last data to the leds again
 	int rewriteLeds();