This is not a real run queue and we're facing ugly bugs because
if this : if a an applet removes another applet from the queue,
typically the next one after itself, the list iterator loops
forever because the list's backup pointer is not valid anymore.
Before creating a run queue, let's rename this list.
The new function is called for each round of polling in order to call any
active appctx. For now we pick the stream interface from the appctx's
owner. At the moment there's no appctx queued yet, but we have everything
needed to queue them and remove them.
