[Doxygen] Exclude binary dir.

Documentation/Doxyfile.in

@@ -830,7 +830,7 @@ EXCLUDE                = ${PROJECT_SOURCE_DIR}/ThirdParty \
                          ${PROJECT_SOURCE_DIR}/Tests \
                          ${PROJECT_SOURCE_DIR}/Documentation/ProjectFile \
                          ${PROJECT_SOURCE_DIR}/web \
-                         ${PROJECT_BINARY_DIR}/External
+                         ${PROJECT_BINARY_DIR}
 
 # The EXCLUDE_SYMLINKS tag can be used to select whether or not files or
 # directories that are symbolic links (a Unix file system feature) are excluded