Factor out app multiplexing from scribe topics.
Add node exclusions to the broadcasts.
Polish a bit the topic unsubscription.
Factor out app multiplexing from scribe.
Fix #15: mark all inbound messages as secure.
More fixes + initial pub/sub test.
Extend pub/sub tests with unsubscriptions.
Scribe balance tests.
Scribe direct messaging test.
Turn iris into an overlay with conn multiplexing.
Add broadcast tests and fix closure bug.
Request/reply tests for iris overlay.
Iris publish/subscribe tests.
Complete tunnel rewrite.
Refactor the relay to use the new iris overlay.