User Event return value

[wiebe@CARYA]

The idea is to add a return value option to user events:

If there are multiple event registrations, the return value is passed through them. Pretty much like existing filter event.

Optional icing on the cake:

Spoiler

The Generate user event could be split up in a send and receive part.

A time out could be added to the receive as well. 

Waiting for return data could be optional. The data will still propagate though all registered event structures. 

Disclaimer

Spoiler

I've read all "User Event" search hits on the idea exchange. Closest\only related one I could find was Register-User-Event-as-Filter-event, which is mostly concerned about discarding the event. But the idea exchange search is terrible, so it could be right under my nose...