py3: make tests/test-diff-antipatience.t work with python 3...
py3: make tests/test-diff-antipatience.t work with python 3
On python3, if we do list(b'abcd'), we get [97, 98, 99, 100]. So this patch does
the list() operation on unicodes and then convert things to bytes.
This also adds `and None` to suppress return values of .write() calls.
Differential Revision:
https://phab.mercurial-scm.org/D3833
