Make some settings only available to group owners and admins

[tanius]

Currently, all of the Open Ethnographer settings can be edited by all users with access to Open Ethnographer (that is, with group membership in group annotator). Theoretically, that allows all users to mess up the data, and the settings of other users.

It would be nice to let "ordinary" Open Ethnographer users only edit settings relevant to them: their own user settings, plus creating a new project, and renaming all projects. (The latter makes no sense anymore if we ever decide to require permissions to work in a project. But so far, that is not the case: every annotator can add annotations in each project, so they may also rename each project.)

All other settings should only be accessible to so-called owners of the group annotator (a Discourse feature), and to Discourse administrators. Not to Discourse moderators, as these do not have access to Open Ethnographer anymore, as long as I remember.