Some fixes / tweaks / Doxygen:

* helper method to detect disconnected state
* clear ATC info if disconnected or not available
* unit test for "finders"
* added Doxygen file
* formatting frequency in text message tabs

src/blacksim/fscommon/aircraftmapping.h

@@ -7,7 +7,7 @@
 #define BLACKSIM_FSCOMMON_AIRCRAFTMAPPING_H
 
 #include "aircraftcfgentries.h"
-#include "../simulatorinfo.h"
+#include "blacksim/simulatorinfo.h"
 #include "blackmisc/valueobject.h"
 #include <QVariant>
 #include <QDateTime>

src/blacksim/simulatorinfolist.h

@@ -3,9 +3,7 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
-/*!
-    \file
-*/
+//! \file
 
 #ifndef BLACKSIM_SIMULATORINFOLIST_H
 #define BLACKSIM_SIMULATORINFOLIST_H