bug 845918: Move exception classes from macros to new errors module
bug 845923: Upgrade node-statsd
bug 845923: Sprinkle statsd measurements everywhere
bug 845918: Update node-hirelings to get the retries option
bug 845923: Use the new Pool.getStats() method from node-hirelings
bug 845918: Attempt to retry failed macros several times
bug 845923: Ensure a statsd instance is available wherever needed
Merge pull request #28 from lmorchard/845918-macro-process-cluster

Tests and spot-check works for me. Let's give this another go.