Workaround doxygen issue.

The root cause seems to be a parsing issue in Doxygen, described in #6528. So given this isn't our own code and we want to keep the numbner of patches that need to be applied to a minimum, tell Doxygen to ignore the lua source directory entirely.

This does then (somehow) reveal another issue in another unrelated source file where it's referencing a method in its documentation that doesn't actually exist.

Fixes #6528

Doxyfile

@@ -905,7 +905,8 @@ EXCLUDE_SYMLINKS       = NO
 # Note that the wildcards are matched against the file with absolute path, so to
 # exclude all test directories for example use the pattern */test/*
 
-EXCLUDE_PATTERNS       = */src/modules/*
+EXCLUDE_PATTERNS       = */src/modules/* \
+                         */src/lua/*
 
 # The EXCLUDE_SYMBOLS tag can be used to specify one or more symbol names
 # (namespaces, classes, functions, etc.) that should be excluded from the

src/whiteboard/action.hpp

@@ -101,7 +101,7 @@ public:
 	/**
 	 * Possible errors.
 	 *
-	 * Returned by the @ref check function.
+	 * Returned by the @ref check_validity function.
 	 */
 	enum error
 	{