Made the edit deployment partial optional

(cherry picked from commit 126372f2e385024da705b382ee96ae87bc3e9b2c)
Improve comment about new role_constraints

(cherry picked from commit d1b2b4506bdc6d12c37e8bbe8753a10b58b2305a)
Merge pull request #974 from vuntz/release/roxy/master

Backport the role_constraints bit to roxy