Base: split export/import macros from FCConfig.h and move them to FCGlobal.h

The FCGlobal.h can be included in a Global.h header file of an extension module.

The reason is that some IDEs (e.g. QtCreator) fails to detect the export/import macros when only defined in the PreCompiled.h files and thus raise a parser warning.

src/Base/Matrix.h

@@ -25,12 +25,15 @@
 #define BASE_MATRIX_H
 
 #include <cassert>
+#include <cfloat>
 #include <cmath>
 #include <cstdio>
 #include <string>
 
 #include "Vector3D.h"
-#include <float.h>
+#ifndef FC_GLOBAL_H
+#include <FCGlobal.h>
+#endif
 
 namespace Base {