publish keepalives for server-sent events
publish keepalives for server-sent events

These should keep the connection alive. This may cause additional load
on the server and/or clients, but should improve the experience. If it
does cause problems, the window can be lengthened.

wuvt/wuvt-site,wuvt/wuvt-site,wuvt/wuvt-site,wuvt/wuvt-site