py3: fix up test-encoding-align.t for python3
I'm not super thrilled with how this reads, but the original didn't
thrill me either.
Differential Revision: https://phab.mercurial-scm.org/D5682
py3: these two casefolding tests pass for me on my Mac
I assume the buildbot didn't catch them because it's on a
case-sensitive filesystem.
Differential Revision: https://phab.mercurial-scm.org/D5681
py3: port test-bugzilla.t to Python 3
Some assorted fixes required in the extension itself, all around
bytes/str issues.
Differential Revision: https://phab.mercurial-scm.org/D5680