* h_version-control/: estet
pfff: test infrastructure for git API

Summary:
Before adding support for mercurial in pfff/h_version-control, it's
good to put first some basic test infrastructure.

Test Plan: make  test

Reviewers: jiaol, pieter

Reviewed By: pieter

CC: pieter

Differential Revision: https://phabricator.fb.com/D892210

Task ID: 2228702
pfff: added a Git.grep and unit tests for Git.grep

Test Plan: make test

Reviewers: jiaol, pieter

Reviewed By: pieter

CC: pieter

Differential Revision: https://phabricator.fb.com/D892280

Task ID: 2228702
pfff: added a Git.show and unit tests for it

Test Plan: make test

Reviewers: jiaol, sid0

Reviewed By: jiaol

CC: pieter

Differential Revision: https://phabricator.fb.com/D892356

Task ID: 2228702
* h_version-control/git.ml: remove use of open Common2
pfff: added a Mercurial.grep

Summary: One of this command will be useful for cmf --deadcode

Test Plan: make test

Reviewers: jiaol

Reviewed By: jiaol

CC: pieter

Differential Revision: https://phabricator.fb.com/D893009

Task ID: 2228702
pfff: added a Mercurial.show

Test Plan: make test

Reviewers: jiaol

Reviewed By: jiaol

CC: pieter

Differential Revision: https://phabricator.fb.com/D893103

Task ID: 2228702
pfff: Mercurial.files_involved_in_diff

Summary: Last piece needed for cmf --deadcode.

Test Plan: make test

Reviewers: jiaol, sid0

Reviewed By: jiaol

CC: pieter, sid0

Differential Revision: https://phabricator.fb.com/D893270

Task ID: 2228702
pfff: add generic interface abstracting away the concrete VCS (git or hg)

Summary: This is needed for cmf --deadcode.

Test Plan: make test

Reviewers: jiaol

Reviewed By: jiaol

CC: pieter, sid0

Differential Revision: https://phabricator.fb.com/D893856

Task ID: 2228702