3.57v

1. New widget offline form will support file field now.
2. Webhook has option to set alternative scenario of conditions are not met.
3. Change how soft limit is calculated for department load statistic.
4. Popup was not showing offline form even argument was passed in embed code.
5. Dashboard open chats has sub-tabs instead of list one after another.
6. Start chat custom field settings was not setting required attribute if not first one was checked.
7. Webhooks conditions can be applied to standard events now.
8. JS API to send messages as visitor from third party JS.
9. Images will show download icon always.
10. If sending message to chat fails we will show an error to visitor.

execute doc/update_db/update_230.sql for update