D210: pushvars: move fb extension pushvars to core

[pulkit (Pulkit Goyal)]

pulkit added inline comments.

INLINE COMMENTS

> akushner wrote in commands.py:4012-4016
> This should definitely be opt-in, vs. opt-out.

Sorry but I don't understand what you mean here. Do I need to change the documentation part or the change the flag part. Currently I have set the default of the flag to True.

REPOSITORY
  rHG Mercurial

REVISION DETAIL
  https://phab.mercurial-scm.org/D210

To: pulkit, #hg-reviewers
Cc: akushner, mercurial-devel