Summary:
This basically takes the last upstream version of my conflictinfo patch and makes it an extension, so we can get it out to FB/Nuclide users
a bit faster. @asriram has already been developing with this version as a personal extension for a couple of weeks.
I still plan to ship the upstream version through after the freeze ends -- when that happens, we can delete this extension. During the time the two
versions overlap, they shouldn't conflict. (The extension version will still run over the internal version until it's disabled, though.)
Review-wise, this is similar to the last upstream version, except it adds the "command" key that indicates which command generated the conflicts (based on which mutually-exclusive state file exists), and incorporates most of the feedback.
Test Plan: Added a test and ran associated tests.
Reviewers: #mercurial, rmcelroy
Reviewed By: rmcelroy
Subscribers: rmcelroy, asriram, mjpieters
Differential Revision: https://phabricator.intern.facebook.com/D4944709
Signature: t1:4944709:1493148790:a4e798f5bd17ada767ae6c96fe8c8ab973960383
