Issue #18457: Fixed saving of formulas and complex numbers in Tools/demo/ss1.py.

Useed context managers for file I/O.
Removed out-of-dated code and misleading comments.

diff --cc Misc/NEWS
index 69d944a93356d3df751ce9d21fdb0a7d4eb2511a,816a526ed67008f5cc121dcc5a8dd696f1a1d001..290c9881858e73af26a75c4684d48c7fa9ab33e3
--- 1/Misc/NEWS
--- 2/Misc/NEWS
+++ b/Misc/NEWS
@@@ -659,25 -492,27 +659,28 @@@ IDL
  Build
  -----
  
 -- Issue #17547: In configure, explicitly pass -Wformat for the benefit for GCC
 -  4.8.
 -
 -- Issue #17962: Build with OpenSSL 1.0.1e on Windows.
 -
 +- Issue #17845: Clarified the message printed when some module are not built.
  
 -What's New in Python 3.3.1?
 -===========================
 +- Issue #18256: Compilation fix for recent AIX releases.  Patch by
 +  David Edelsohn.
  
 -*Release date: 07-Apr-2013*
 +- Issue #17547: In configure, explicitly pass -Wformat for the benefit for GCC
 +  4.8.
  
 -Build
 ------
 +- Issue #15172: Document NASM 2.10+ as requirement for building OpenSSL 1.0.1
 +  on Windows.
  
 -- Issue #17550: Fix the --enable-profiling configure switch.
 +Tools/Demos
 +-----------
  
 -IDLE
 --------
++- Issue #18457: Fixed saving of formulas and complex numbers in
++  Tools/demo/ss1.py.
+ 
 -- Issue #17625: In IDLE, close the replace dialog after it is used.
 +- Issue #18449: Make Tools/demo/ss1.py work again on Python 3.  Patch by
 +  Févry Thibault.
  
 +- Issue #12990: The "Python Launcher" on OSX could not launch python scripts
 +  that have paths that include wide characters.
  
  What's New in Python 3.3.1 release candidate 1?
  ===============================================