hgweb: extract code for emitting multiple changelist records changelistentry() exists so extensions can easily monkeypatch the function to add additional metadata. In at least one case at Mozilla, we have an extension doing this where performance would greatly benefit if we were able to "batch fetch" metadata for all revisions that will eventually have their data set. By extracting the logic for "obtain records for N revisions" into a standalone function, we make it possible for a monkeypatched function to more efficiently bulk fetch data for N revisions. Differential Revision: https://phab.mercurial-scm.org/D3573

phabricator: register config settings I didn't bother registering the deprecated phabricator.auth.*, and I'm not sure if the two flagged as 'developer config' should be moved to [devel] (or why there's a distinction between `repophid` and `callsign`).

filemerge: support specifying a python function to custom merge-tools Eliminates the need to specify a python executable, which may not exist on system. Additionally launching script inprocess aids portability on systems that can't execute python via the shell. Example usage "merge-tools.myTool.executable=python:c:\myTool.py:mergefn" where myTool.py contains a function: "def mergefn(ui, repo, args, **kwargs):" where args is list of args passed to merge tool. (by default, expanded: $local $base $other) Invoking the specified python function was done by exposing and invoking (hook._pythonhook -> hook.pythonhook)

help: correct signature of separate() template function Without the dots, it looked as if separate() would take a list of arguments.

hgweb: do not try to replace signal handlers while locking According to the issue 5889, mod_wsgi issues a warning on signal.signal() call, and we wouldn't want to see it in error log. The problem addressed by d77c3b023393 could potentially occur in web session, but that would be less likely than in user processes.

lock: add internal config to not replace signal handlers while locking signal.signal() is blocked in some WSGI environments, and a horrible warning is sent to the server log. So we need a way to disable it, and I think abusing ui.config is the simplest workaround.