Copied code from __getitem__ to __setitem__ . This fixes one error in
test_base and brings up a new error:

line 1172
A[1:3, 1] = [[10], [20]]
now works

line 984
A[1:5, 0] = range(1, 5)
is now broken

line 984 does not work for NumPy matrix objects, so I think that test should
be deleted. I'm leaving that alone for now.