doc: Move deprecated modules into separate section

doc/lib.txt

@@ -201,12 +201,6 @@ Internet Protocols and Support
 * `scgi <scgi.html>`_
   This module implements helpers for SCGI applications.
 
-* `sockets <sockets.html>`_
-  This module implements a simple portable type-safe sockets layer.
-
-* `asyncio <asyncio.html>`_
-  This module implements an asynchronous event loop for sockets.
-
 * `browsers <browsers.html>`_
   This module implements procs for opening URLs with the user's default
   browser.
@@ -220,9 +214,6 @@ Internet Protocols and Support
 * `smtp <smtp.html>`_
   This module implement a simple SMTP client.
 
-* `ftpclient <ftpclient.html>`_
-  This module implements an FTP client.
-
 * `cookies <cookies.html>`_
   This module contains helper procs for parsing and generating cookies.
 
@@ -397,6 +388,27 @@ Modules for JS backend
   Declaration of the Document Object Model for the JS backend.
 
 
+Deprecated modules
+------------------
+
+* `asyncio <asyncio.html>`_
+  This module implements an asynchronous event loop for sockets.
+  **Deprecated since version 0.11.2:**
+  Use the `asyncnet <asyncnet.html>`_ together with the
+  `asyncdispatch <asyncdispatch.html>`_ module instead.
+
+* `ftpclient <ftpclient.html>`_
+  This module implements an FTP client.
+  **Deprecated since version 0.11.3:**
+  Use the `asyncftpclient <asyncftpclient.html>`_ module instead.
+
+* `sockets <sockets.html>`_
+  This module implements a simple portable type-safe sockets layer.
+  **Deprecated since version 0.11.2:**
+  Use the `net <net.html>`_ or the `rawsockets <rawsockets.html>`_ module
+  instead.
+
+
 Impure libraries
 ================