why this breaks on openbsd sometimes.

imports of test modules now import from the test package.  Other
related oddities are also fixed (like DeprecationWarning filters that
weren't specifying the full import part, etc.).  Also did a general
code cleanup to remove all "from test.test_support import *"'s.  Other
from...import *'s weren't changed.

mostly changes of / operators into //.  Once or twice I did more or
less than recommended.

+ test_compare.  While None compares less than anything else, it's not
  always the case that None has the smallest id().
+ test_descr.  The output of %p (pointer) formats varies across platforms.
  In particular, on Windows it doesn't produce a leading "0x".

that class should compare the id() of those instances.  Add a test
that verifies this.  This test currently fails; I believe this is
caused by object.c:2.132 (Patch #424475 by loewis).

comparing different types.

overhaul.  Closes SF patch #102878.