Merge 3.3.

diff --cc Lib/decimal.py
Simple merge

diff --cc Misc/NEWS
index d52a9d81599322c5d8bef15bf35bdd761aa33645,e396da9e8f64dd8fd88190b80f2f9ab60368607b..3135c33609445352cdf2909745789b819bd45b6e
--- 1/Misc/NEWS
--- 2/Misc/NEWS
+++ b/Misc/NEWS
@@@ -167,12 -108,10 +167,16 @@@ Core and Builtin
  Library
  -------
  
+ - Issue #15783: Except for the number methods, the C version of decimal now
+   supports all None default values present in decimal.py. These values were
+   largely undocumented.
+ 
 +- Issue #11175: argparse.FileType now accepts encoding and errors
 +  arguments. Patch by Lucas Maystre.
 +
 +- Issue #16488: epoll() objects now support the `with` statement.  Patch
 +  by Serhiy Storchaka.
 +
  - Issue #16298: In HTTPResponse.read(), close the socket when there is no
    Content-Length and the incoming stream is finished.  Patch by Eran
    Rundstein.