Added keyboard response functionality: Now it is possible to stop GNSS-SDR from the keyboard order "q"+ENTER

git-svn-id: https://svn.code.sf.net/p/gnss-sdr/code/trunk@186 64b25241-fba3-4117-9849-534c7e92360d

src/core/receiver/control_thread.h

@@ -37,6 +37,7 @@
 
 #include <gnuradio/gr_msg_queue.h>
 #include "control_message_factory.h"
+#include <boost/thread/thread.hpp>
 
 class GNSSFlowgraph;
 class ConfigurationInterface;
@@ -123,6 +124,8 @@ private:
 
     unsigned int processed_control_messages_;
     unsigned int applied_actions_;
+    boost::thread keyboard_thread_;
+    void keyboard_listener();
 };
 
 #endif /*GNSS_SDR_CONTROL_THREAD_H_*/