Add version info for os.kill and signal changes from #1220212.

Doc/library/os.rst

@@ -1735,6 +1735,8 @@ written in Python, such as a mail server's external command delivery program.
    will be set to *sig*. The Windows version of :func:`kill` additionally takes
    process handles to be killed.
 
+   .. versionadded:: 2.7 Windows support
+
 
 .. function:: killpg(pgid, sig)
 

Doc/library/signal.rst

@@ -78,16 +78,18 @@ The variables defined in the :mod:`signal` module are:
 .. data:: CTRL_C_EVENT
 
    The signal corresponding to the CTRL+C keystroke event.
-
    Availability: Windows.
 
+   .. versionadded:: 2.7
+
 
 .. data:: CTRL_BREAK_EVENT
 
    The signal corresponding to the CTRL+BREAK keystroke event.
-
    Availability: Windows.
 
+   .. versionadded:: 2.7
+
 
 .. data:: NSIG