templater: restore the original string format of {date} Unfortunately, python-hglib relies on that. I could fix python-hglib, but there would be other tools that take a decimal separator as the separator of unixtime and tzoffset. The showfmt is set per instance since new code uses '%d %d' format by default.

hgweb: insist http_status value is a sysstr My previous change was extremely confusing to figure out, because I thought I was looking at a client-side problem. For the low cost of an isinstance assert, we can make those errors not happen in the future. Differential Revision: https://phab.mercurial-scm.org/D3727

hgweb: pass a sysstr to low-level _start_response method This fixes a regression in Python 3 support introduced in 7de7bd407251 on the stable branch. We're so early in do_hgweb that I don't see any especially better choices than this. Differential Revision: https://phab.mercurial-scm.org/D3726

tests: fix printenv script on Python 3 Differential Revision: https://phab.mercurial-scm.org/D3725

cvsps: port changeset __repr__ to py3 This appears to be unused except as a debugging aid, as it didn't break until I added a debug print() in service of the previous fix. Sigh. Differential Revision: https://phab.mercurial-scm.org/D3724

cvsps: avoid comparison between None and a tuple in date sorting Avoids badness on Python 3. I had to figure out which entries in this object *could* be None experimentally, but I think I've got them all now. Differential Revision: https://phab.mercurial-scm.org/D3723