Oops, used a \label twice - fix one of them.

Doc/lib/libformatter.tex

@@ -302,7 +302,7 @@ will only be called at the beginning of a line.
 \end{methoddesc}
 
 
-\subsection{Writer Implementations \label{formatter-impls}}
+\subsection{Writer Implementations \label{writer-impls}}
 
 Three implementations of the writer object interface are provided as
 examples by this module.  Most applications will need to derive new