obsmarker: track operation by default
We added support for including the operation responsible for creating
the obsmarker in
3546a771e376 (obsolete: add operation metadata to
rebase/amend/histedit obsmarkers, 2017-05-09). However, soon
thereafter, in
f432897a9f49 (obsmarker: add an experimental flag
controlling "operation" recording, 2017-05-20), it was hidden behind a
config that was off by default. It seems unlikely that people will
manually turn it on, and obsmarkers/evolution as a whole is still
experimental anyway, so let's turn on the tracking by default.
Differential Revision: https://phab.mercurial-scm.org/D722
#require docutils gettext
$ $TESTDIR/check-gendoc sv
checking for parse errors