Editing/Deleting a shared project by members should not be possible

Currently the admin can do more on his own project (change members, upload and op size limit), but a simple member of that project can still change its name, description or delete the project.

I think none of the actions should be permitted for the members, but instead we should make all fields read-only, and add one new button for members to opt-out of being member of the current project.

Changes in edit_one.html are expected for this.

To be added unit-tests