If a group Member is clicked and their settings changed (for example, changing their role to Moderator and checking/unchecking various options), then:
If the "Send Message" button at the bottom is clicked instead of "Save", the changes are lost.
Change the "Send Message" button to "Save Changes and Send Message" (would be very useful!)
Prompt the user to Save or Discard first, if "Send Message" is clicked
Disable all buttons other than "Save" and "Discard" as soon as any setting is changed
If "Send Message" is clicked, return to the member-edit dialog afterwards (with the state as it was)