Mailster - Email Newsletter Plugin for WordPress 4.1.12

- fixed: missing capability to delete campaigns in some case
- fixed: missing key in array function
- added: new capabilities `delete_private_newsletters`, `delete_published_newsletters`
- improved: alignment of elements in the automation inspector
- improved: use `ToggleGroupControl` on update custom field action for checkboxes
- package upgrades

- fixed: bug when subscribe on multiple lists. 'wpdb->delete' may return 0 so do better checks
- removed redundant shortcode
- updated packages

- fixed: issue where activating caused a fatal error if `wp_mail` is used by another plugin
- fixed: typo
- updated: Freemius SDK to 2.10.1