Server shuts down on permanent listener failure
Fix peer/liveness test

Use ResolveUDPAddr instead of direct allocation.
Use UDP address resolution instead of allocation
Fix reported data race condition in consensus test
Triggers are sorted by time and sequence number

It was previously assumed that calling:

    heap.Push(triggers, trigger{t: 123, n: 2})
    heap.Push(triggers, trigger{t: 123, n: 1})

Would produce `[{t:123, n:1}, {t:126, n:2}]`, but that is not the case
in go1.1.
Merge pull request #61 from bernerdschaefer/fix/tests-and-go-1.1

Go 1.1 compatibility, prevent hanging tests