RemotePlugin: allow waitForInitDone() without busy waiting

An additional parameter to waitForInitDone() allows to disable busy
waiting which could be desired in various places to avoid deadlocks.
(cherry picked from commit 1802b91e55)

include/remote_plugin.h

@@ -681,9 +681,10 @@ public:
 		return m_process.state() != QProcess::NotRunning;
 	}
 
-	inline void waitForInitDone( void )
+	inline void waitForInitDone( bool _busy_waiting = true )
 	{
-		m_failed = waitForMessage( IdInitDone, true ).id != IdInitDone;
+		m_failed = waitForMessage( IdInitDone,
+					_busy_waiting ).id != IdInitDone;
 	}
 
 	virtual bool processMessage( const message & _m );