Typo fix.

Doc/api/api.tex

@@ -1402,7 +1402,7 @@ internal table.  This should be called before
 \end{cfuncdesc}
 
 
-\section{Parsing arguements and building values
+\section{Parsing arguments and building values
          \label{arg-parsing}}
 
 These functions are useful when creating your own extensions functions