Inform user about current branch in diff
Inform user about current branch in diff

Summary: I am trying to stop using `--verbatim` and miss this information.

Test Plan: This diff.

Reviewers: epriestley

Reviewed By: epriestley

CC: aran, Koolvin

Differential Revision: https://secure.phabricator.com/D2575

chundongwang/arcanist,wxstars/arcanist,dguo-coursera/arcanist,Khan/arcanist,r4nt/arcanist,zhihu/arcanist,phacility/arcanist,codelabs-ch/arcanist,Symplicity/arcanist,alexmv/arcanist,uber/arcanist,dguo-coursera/arcanist,fivestars/arcanist,wxstars/arcanist,julkiewicz/arcanist,phacility/arcanist,wikimedia/phabricator-arcanist,phacility/arcanist,memsql/arcanist,Khan/arcanist,fivestars/arcanist,coursera/arcanist,coursera/arcanist,PageUpPeopleOrg/arcanist-patches,chundongwang/arcanist,dguo-coursera/arcanist,haskell-infra/arcanist,PageUpPeopleOrg/arcanist-patches,phacility/arcanist,zhihu/arcanist,wharris/arcanist,Symplicity/arcanist,dguo-coursera/arcanist,kevinseelbach/arcanist,wxstars/arcanist,coursera/arcanist,fivestars/arcanist,julkiewicz/arcanist,uber/arcanist,hach-que/arcanist,KieranHayes/arcanist,PageUpPeopleOrg/arcanist-patches,wxstars/arcanist,PageUpPeopleOrg/arcanist-patches,folsom-labs/arcanist,folsom-labs/arcanist,Symplicity/arcanist,codelabs-ch/arcanist,Symplicity/arcanist,aik099/arcanist,jra3/arcanist,codelabs-ch/arcanist,zhihu/arcanist,sneakpeeq/arcanist,haskell-infra/arcanist,jra3/arcanist,sneakpeeq/arcanist,wharris/arcanist,memsql/arcanist,calblueprint/arcanist,haskell-infra/arcanist,aik099/arcanist,haskell-infra/arcanist,wharris/arcanist,alexmv/arcanist,wharris/arcanist,calblueprint/arcanist,wikimedia/phabricator-arcanist,fivestars/arcanist,wikimedia/phabricator-arcanist,eSpark/arcanist,KieranHayes/arcanist,uber/arcanist,wikimedia/phabricator-arcanist,r4nt/arcanist,KieranHayes/arcanist,memsql/arcanist,calblueprint/arcanist,sneakpeeq/arcanist,sneakpeeq/arcanist,uber/arcanist,memsql/arcanist,hach-que/arcanist,julkiewicz/arcanist,zhihu/arcanist,aik099/arcanist,Khan/arcanist,eSpark/arcanist,eSpark/arcanist,julkiewicz/arcanist,r4nt/arcanist,codelabs-ch/arcanist,r4nt/arcanist,alexmv/arcanist,kevinseelbach/arcanist,chundongwang/arcanist,calblueprint/arcanist,eSpark/arcanist,Khan/arcanist,hach-que/arcanist,coursera/arcanist,alexmv/arcanist,phacility/arcanist,jra3/arcanist,aik099/arcanist,kevinseelbach/arcanist,KieranHayes/arcanist,jra3/arcanist,chundongwang/arcanist,folsom-labs/arcanist,kevinseelbach/arcanist,hach-que/arcanist,codelabs-ch/arcanist,folsom-labs/arcanist