Summary:
People want update to optionally not activate a bookmark.
This diff adds an `--inactive` flag to do that.
Test Plan: Added test-update-i.t
Reviewers: durham, #mercurial, quark
Reviewed By: quark
Subscribers: mitrandir, mjpieters, medson, durham, akushner, quark
Differential Revision: https://phabricator.intern.facebook.com/D5228552
Tasks: 8097957
Signature: t1:5228552:1497396566:16322e1a2dfdab30a213ddc37cbde4fc71bffcc0
