remove mail domain add/remove API

merge this as a transaction into domains API

fixes #669

src/test/apps-test.js

@@ -15,6 +15,7 @@ var appdb = require('../appdb.js'),
     groupdb = require('../groupdb.js'),
     groups = require('../groups.js'),
     hat = require('../hat.js'),
+    settings = require('../settings.js'),
     userdb = require('../userdb.js');
 
 let AUDIT_SOURCE = { ip: '1.2.3.4' };
@@ -173,6 +174,7 @@ describe('Apps', function () {
         async.series([
             database.initialize,
             database._clear,
+            settings.setAdmin.bind(null, DOMAIN_0.domain, 'my.' + DOMAIN_0.domain),
             domains.add.bind(null, DOMAIN_0.domain, DOMAIN_0, AUDIT_SOURCE),
             domains.add.bind(null, DOMAIN_1.domain, DOMAIN_1, AUDIT_SOURCE),
             userdb.add.bind(null, ADMIN_0.id, ADMIN_0),