Adds a role setting for controlling visibility of users: all or members of visible projects (#11724).

git-svn-id: http://svn.redmine.org/redmine/trunk@13584 e93f8b46-1217-0410-a6f0-8f06a7374b81
Adds strings to locales (#11724).

git-svn-id: http://svn.redmine.org/redmine/trunk@13585 e93f8b46-1217-0410-a6f0-8f06a7374b81
Display visible users only for when adding project members (#11724).

git-svn-id: http://svn.redmine.org/redmine/trunk@13586 e93f8b46-1217-0410-a6f0-8f06a7374b81
Don't load user activity for API responses (#18128).

git-svn-id: http://svn.redmine.org/redmine/trunk@13587 e93f8b46-1217-0410-a6f0-8f06a7374b81