Added kill, terminate and send_signal to subprocess.Popen
The bits and pieces for the Windows side were already in place. The POSIX side is trivial (as usual) and uses os.kill().
diff --git a/Misc/NEWS b/Misc/NEWS
index 6ae6e46..660651a 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -18,6 +18,8 @@
 Extensions Modules
 ------------------
 
+- Added kill, terminate and send_signal(sig) to subprocess.Popen.
+
 - Added phase(z) -> phi, polar(z) -> r, phi and rect(r, phi) -> z to the cmath
   module.