procutil: redirect ui.fout to stderr while stdio is protected The new behavior seems slightly nicer as we can at least read the output. And this is similar to what the sshserver is doing, so we can probably reuse protectstdio() instead of the weird hook.redirect(True) hack.

procutil: unroll uin/uout loop in protectstdio() I'll change uout to be redirected to stderr.

context: drop support for changeid of type long (API?) I don't see a reason to support type long. It's pretty much the same type as int. There was some discussion about it on the mailing list around the time of ff2f90503d64 (context: work around `long` not existing on Python 3, 2017-03-11), but I couldn't find a good reason to keep it. There was some mention of hgtk doing "repo[long(rev)]", but that was in 2012. Differential Revision: https://phab.mercurial-scm.org/D2989