Core and builtins
-----------------
-- Bug #1776: __import__ must not accept filenames. Python 2.6 does no longer
- support module loading by filename. It worked on some system by coincident
- but it was never intended to work.
+- Bug #1776: __import__() no longer accepts filenames on any platform.
+ The first parameter to __import__() must be a valid module name.
- Patch #1668: renamed THREADDEBUG envvar to PYTHONTHREADDEBUG.