Add version added info for with statement and context managers
diff --git a/Doc/lib/libcontextlib.tex b/Doc/lib/libcontextlib.tex
index 842c954..46f9cdd 100644
--- a/Doc/lib/libcontextlib.tex
+++ b/Doc/lib/libcontextlib.tex
@@ -4,6 +4,8 @@
\declaremodule{standard}{contextlib}
\modulesynopsis{Utilities for \keyword{with}-statement contexts.}
+\versionadded{2.5}
+
This module provides utilities for common tasks involving the
\keyword{with} statement.
diff --git a/Doc/ref/ref3.tex b/Doc/ref/ref3.tex
index dfd4102..48a37f1 100644
--- a/Doc/ref/ref3.tex
+++ b/Doc/ref/ref3.tex
@@ -2109,6 +2109,8 @@
\subsection{Context Managers and Contexts\label{context-managers}}
+\versionadded{2.5}
+
A \dfn{context manager} is an object that manages the entry to, and exit
from, a \dfn{context} surrounding a block of code. Context managers are
normally invoked using the \keyword{with} statement (described in
diff --git a/Doc/ref/ref7.tex b/Doc/ref/ref7.tex
index a5a6eaf..ecbc756 100644
--- a/Doc/ref/ref7.tex
+++ b/Doc/ref/ref7.tex
@@ -312,6 +312,8 @@
\section{The \keyword{with} statement\label{with}}
\stindex{with}
+\versionadded{2.5}
+
The \keyword{with} statement is used to wrap the execution of a block
with methods defined by a context manager (see
section~\ref{context-managers}). This allows common