py3: fix couple of division operator to do integer divison Differential Revision: https://phab.mercurial-scm.org/D5305

py3: use dict.items() instead of dict.iteritems() dict.iteritems() does not exist on Python 3. Differential Revision: https://phab.mercurial-scm.org/D5304

py3: convert strings to bytes in tests/test-remotefilelog-histpack.py Differential Revision: https://phab.mercurial-scm.org/D5303

py3: replace str() with pycompat.bytestr() or ('%d' % int) After this patch, test-fastannotate-diffopts.t is about to pass. There are some extra newlines in the output. Differential Revision: https://phab.mercurial-scm.org/D5300

perf: add a `--timing` argument to `perfhelper-tracecopies` The new argument will help picking better pair for benchmarking. See documentation for details.

ui: manage logger instances and event filtering by core ui The setup code in blackbox needs more tweaks since it has lots of black magics. I'll fix them by follow-up patches. To be clear, the goal of this series is to provide a proper way for command server to install its own logger. I need it to debug in-memory repository cache.

extensions: add "uipopulate" hook, called per instance, not per process In short, this is the "reposetup" function for ui. It allows us to modify ui attributes without extending ui.__class__. Before, the only way to do that was to abuse the config dictionary, which is copied across ui instances. See the next patch for usage example.

hgweb: load globally-enabled extensions explicitly Before, extensions were loaded as a side effect of hg.repository() if the hgweb was executed as a CGI/WSGI. I want to make it explicit so that another ui hook can be inserted after extensions.loadall().