Feature: Message for EventSender dispatch

Merge @bobbybee's Datagram EventSender implementation for https://github.com/Astron/Astron/issues/263
My bad for not spotting this in master, but Windows doesn't play nicely when you try to remove the temp file:

```
WindowsError: [Error 32] The process cannot access the file because it is being used by another process: 'c:\\users\\harvir\\appdata\\local\\temp\\astron-ck4hhw.log'
```