Allow --verbatim and -m in arc diff
Allow --verbatim and -m in arc diff

Summary:
There's no reason these should be exclusive: -m is used only on update for the
update message, and --verbatim doesn't affect the udpate message. It's also
useful to allow both of these, if say I want to update my test plan by editing
my git commit message and also provide a message for the update from the
command line.

Test Plan:
ran arc diff with --verbatim and -m and saw my message from -m was used, as
well as my updates in the commit message went through.

Reviewers: jungejason, epriestley, vrana

Reviewed By: epriestley

CC: aran, Koolvin

Differential Revision: https://secure.phabricator.com/D2426

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