add doc of permissions argument to role update
1116825 - Adding a non-existent user to a role now returns HTTP 400 instead of 404.
Merge pull request #1310 from jeremycline/1116825

1116825 - Adding a non-existent user to a role now returns HTTP 400 instead of 404.
Merge branch '1066022' into 2.4-release
Merge branch '2.4-testing' into 2.5-testing
Merge branch '2.5-testing' into 2.6-dev