Implement dummy body message to indicate high priority push This adds a dummy body sent alongside the push when the original message also contained a body to indicate a high priority push. The body can be configured and its contents are generally meaningless with most app servers because it will be stripped before pushed to the client.

This module produces more detailed HTTP logs for Prosodys built-in HTTP
server. The format is similar to that of Apache and go into Prosodys
normal logs at the `info` level.