Exclude visibility macros from documentation.

src/Plugins/TgaImporter/TgaImporter.h

@@ -21,6 +21,7 @@
 
 #include "Trade/AbstractImporter.h"
 
+#ifndef DOXYGEN_GENERATING_OUTPUT
 #ifdef _WIN32
     #ifdef TgaImporter_EXPORTS
         #define TGAIMPORTER_EXPORT __declspec(dllexport)
@@ -32,6 +33,7 @@
     #define TGAIMPORTER_EXPORT __attribute__ ((visibility ("default")))
     #define TGAIMPORTER_LOCAL __attribute__ ((visibility ("hidden")))
 #endif
+#endif
 
 namespace Magnum { namespace Trade { namespace TgaImporter {