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.
is no __getslice__ available. Also does the same for C extension types.
Includes rudimentary documentation (it could use a cross reference to the
section on slice objects, I couldn't figure out how to do that) and a test
suite for all Python __hooks__ I could think of, including the new
behaviour.