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

plugins/samplesource/hackrfinput/hackrfinput.cpp

@@ -119,6 +119,11 @@ bool HackRFInput::openDevice()
     return true;
 }
 
+void HackRFInput::init()
+{
+    applySettings(m_settings, true);
+}
+
 bool HackRFInput::start()
 {
 //	QMutexLocker mutexLocker(&m_mutex);

plugins/samplesource/hackrfinput/hackrfinput.h

@@ -114,6 +114,7 @@ public:
 	virtual ~HackRFInput();
 	virtual void destroy();
 
+    virtual void init();
 	virtual bool start();
 	virtual void stop();