Merge 3.3

diff --cc Lib/test/test_multiprocessing.py
Simple merge

diff --cc Misc/ACKS
Simple merge

diff --cc Misc/NEWS
index db55df1fdc00133907dc55a43c346ac0c8391d31,9766633f7cdc6c4395e8702c8899cc8078899a0f..a82b6ca1f58a69cebefcd7b8a994a7cf88bef6ea
--- 1/Misc/NEWS
--- 2/Misc/NEWS
+++ b/Misc/NEWS
@@@ -62,8 -49,10 +62,11 @@@ Core and Builtin
  Library
  -------
  
 -- Issue #16250: Fix URLError invocation with proper args.
+ - Issue #16307: Fix multiprocessing.Pool.map_async not calling its callbacks.
+   Patch by Janne Karila.
+ 
 +- Issue #16305: Fix a segmentation fault occurring when interrupting
 +  math.factorial.
  
  - Issue #16116: Fix include and library paths to be correct when building C
    extensions in venvs.