clean-up guidance code/code in general

removes duplicated includes
removes unused includes
eliminates dedicated toolkits that resulted in circular dependencies
moves functionality close to data, where possible

src/engine/api/json_factory.cpp

@@ -6,7 +6,6 @@
 
 #include "util/guidance/bearing_class.hpp"
 #include "util/guidance/entry_class.hpp"
-#include "util/guidance/toolkit.hpp"
 #include "util/typedefs.hpp"
 
 #include <boost/assert.hpp>