Device sink plugins: implemented an init method for initializations to be done when all collaborating objects are created and possibly connected

plugins/samplesink/hackrfoutput/hackrfoutput.cpp

@@ -104,6 +104,11 @@ bool HackRFOutput::openDevice()
     return true;
 }
 
+void HackRFOutput::init()
+{
+    applySettings(m_settings, true);
+}
+
 bool HackRFOutput::start()
 {
     if (!m_dev) {

plugins/samplesink/hackrfoutput/hackrfoutput.h

@@ -94,6 +94,7 @@ public:
 	virtual ~HackRFOutput();
 	virtual void destroy();
 
+    virtual void init();
 	virtual bool start();
 	virtual void stop();