refs #507, split up blackmiscfreefunctions

* single register metadata functions
* string utils
* metadata utils
* some formatting / license header where applicable

src/blackmisc/aviation/aircraftlights.cpp

@@ -9,6 +9,7 @@
 
 #include "aircraftlights.h"
 #include "blackmisc/variant.h"
+#include "blackmisc/stringutils.h"
 
 using namespace BlackMisc;