Show a greyed out notification button if you're not a member of a project

This is a quick fix for #2846 (closed).

If you're not a member of a project, you do not see the notification settings button right now. That is confusing. A temporary fix would be to make this button visiable, inactive, with as hover over a dialog that tells you that you have to be a member of a project to change the setting.

@skyruler can you do this for 8.1?