Don't show *_EXPORT macros in the documentation.

Got broken probably when trying to work around the issues with
CORRADE_DEPRECATED() macro.

Doxyfile

@@ -1653,7 +1653,19 @@ INCLUDE_FILE_PATTERNS  =
 # instead of the = operator.
 
 PREDEFINED             = DOXYGEN_GENERATING_OUTPUT \
-    MAGNUM_BUILD_DEPRECATED CORRADE_DEPRECATED(message)=
+    MAGNUM_BUILD_DEPRECATED CORRADE_DEPRECATED(message)= \
+    MAGNUM_EXPORT= \
+    MAGNUM_AUDIO_EXPORT= \
+    MAGNUM_DEBUGTOOLS_EXPORT= \
+    MAGNUM_MATH_EXPORT= \
+    MAGNUM_MESHTOOLS_EXPORT= \
+    MAGNUM_PLATFORM_EXPORT= \
+    MAGNUM_PRIMITIVES_EXPORT= \
+    MAGNUM_SCENEGRAPH_EXPORT= \
+    MAGNUM_SHADERS_EXPORT= \
+    MAGNUM_SHAPES_EXPORT= \
+    MAGNUM_TEXT_EXPORT= \
+    MAGNUM_TEXTURETOOLS_EXPORT=
 
 # If the MACRO_EXPANSION and EXPAND_ONLY_PREDEF tags are set to YES then
 # this tag can be used to specify a list of macro names that should be expanded.