- Refactoring of the mail sending part. Mail queue (table 'queued') is now used also for all test emails.

- More options how to send test emails.
- Fixed problems with pausing a campaign (#593)
- Started rework of transactional sender of templates (#606), however this contains functionality regression at the moment because it does not interpret templates as HBS. It needs HBS option for templates as described in https://github.com/Mailtrain-org/mailtrain/issues/611#issuecomment-502345227

TODO:
- detect sending errors connected to not able to contact the mailer and pause/retry campaing and queued sending - don't mark the recipients as BOUNCED
- add FAILED campaign state and fall into it if sending to campaign consistently fails (i.e. the error with sending is not temporary)
- if the same happends for queued email, delete the message

server/routes/archive.js

@@ -1,12 +1,12 @@
 'use strict';
 
 const router = require('../lib/router-async').create();
-const CampaignSender = require('../lib/campaign-sender');
+const {CampaignSender} = require('../lib/campaign-sender');
 
 
 router.get('/:campaign/:list/:subscription', (req, res, next) => {
     const cs = new CampaignSender();
-    cs.init({campaignCid: req.params.campaign})
+    cs.initByCampaignCid(req.params.campaign)
         .then(() => cs.getMessage(req.params.list, req.params.subscription))
         .then(result => {
             const {html} = result;