previewPanel for Kwc/Newsletter/Detail is own Tab
deleted setting mailsPerMinute for Kwf/Controller/Action/Cli/Web/NewsletterController.php and added it to newsletter

can be edited in backend now
deleted mailing panel in Kwc/Newsletter/Detail and created startNewsletterPanel

this contains the progressbar for sending mails with some new features:
-> shows speed of newsletter sending
-> shows remaining time for the mails to send

added new startNewsletter button which can configure the sending start time and sending speed of the newsletter
new possibilty to add Recipients to newsletter/queue and start the newsletter

panel recipients show at left side all possible recipients which can be added to queue,
and on the right side you will see the current queue of recipients for sending

on the bottom the new StartSendingPanel is placed where the newsletter can be started