Adds an event to the given connection.
This function is usually called by providers, to inform clients of events that happened during some operation.
As soon as a provider (or a client, it does not matter) calls this function with an
event object which is an error, the connection
object emits the "error" signal, to which clients can connect to be informed of events.
WARNING: the reference to the
event object is stolen by this function!
a Connection object.
is stored internally, so you don't need to unref it.