Summary:
We want to rename away from "mercurial". Rather than rename the "mercurial" Python package, we opted to just collapse it into the parent "edenscm" package. This is also a step towards further organizing we want to do around the new project name.
To ease the transition wrt hotfixes, we now replace "edenscm.mercurial" with "mercurial" to fix imports within base64-python extensions.
Reviewed By: sggutier
Differential Revision: D38943169
fbshipit-source-id: 03fa18079c51e2f7fac05d65b127095da3ab7c99