Added pause of emitter error until a listener for manage this was setted

[minuyoutility]

In my project i used this solution, instead of emitting immediately the errors, i pause this until an external listener was setted, so this error can be managed from the caller, and if the resolver for manage this wasn't called this not cause a server crash.

[jaydenseric]

Thanks for your contribution! @mike-marcacci and I discussed it in Slack, and decided that there would be edge-cases to this approach that should be solved by #81.