Do not disable mailing lists when disabling a user

Mailing lists have a slightly different concept of "ownership" and we
shouldn't automatically disable them.

Fixes issue #16.

actions_create.go

@@ -277,8 +277,13 @@ func (r *DisableUserRequest) Serve(rctx *RequestContext) (interface{}, error) {
 		return nil, errors.New("user is already inactive")
 	}
 
-	// Disable all resources.
+	// Disable all resources except for lists/newsletters, which
+	// may have multiple ownership and in general have slightly
+	// different "ownership" semantics than other resources.
 	for _, rsrc := range user.Resources {
+		if rsrc.Type == ResourceTypeMailingList || rsrc.Type == ResourceTypeNewsletter {
+			continue
+		}
 		if rsrc.Status == ResourceStatusActive || rsrc.Status == ResourceStatusReadonly {
 			rsrc.Status = ResourceStatusInactive
 			if err := rctx.TX.UpdateResource(rctx.Context, rsrc); err != nil {