Add versionadded info for the 2 new threading module functions

Doc/lib/libthreading.tex

@@ -95,6 +95,7 @@ Set a trace function\index{trace function} for all threads started
 from the \module{threading} module.  The \var{func} will be passed to 
 \function{sys.settrace()} for each thread, before its \method{run()}
 method is called.
+\versionadded{2.3}
 \end{funcdesc}
 
 \begin{funcdesc}{setprofile}{func}
@@ -102,6 +103,7 @@ Set a profile function\index{profile function} for all threads started
 from the \module{threading} module.  The \var{func} will be passed to 
 \function{sys.setprofile()} for each thread, before its \method{run()}
 method is called.
+\versionadded{2.3}
 \end{funcdesc}
 
 Detailed interfaces for the objects are documented below.