optimized Kwc/Mail/Abstract/Component.php, getMediaOutput returns $file now

no need to call Kwf_Media_Output::output($file) directly
enabled duplicating for newsletter component
prefill textfield for testmail sending with currently logged in users email in Kwc/Newsletter/Detail/PreviewPanel
deleting recipients from queue when newsletter is sending is no longer possible
optimized the loading/sending masking in Kwc/Newsletter/Detail/PreviewPanel.js

uses the ajax method mask from Kwf_js/Connection.js
when newsletter is sending now only the pause button will be shown

no editing of newsletter settings if it is not paused
optimized code in Kwc/Newsletter/Detail/MailingFormController.php

code for cards is better now