Added function to restrict online payments, as well as notification about status changes.

Added function to restrict online payments, as well as notification about status changes. You can disable online payment for orders in the general settings, and enable it individually, after checking the availability of goods. After changing the status, you can send an email with a link for payment.

Updated the editor of the Main Menu.
Push notifications have been added.
Added section "Scripts". In which scripts and instructions for them are required for the sites.