bug 845918: Simplify templates test
bug 845918: Ensure a macro with JSON parameter gets exercised
bug 845918: In cached request, consider cached response as revalidated on 304 from origin server; misc bugfixes
bug 845918: Add node-hirelings module
bug 845918: Rework MacroProcessor and associated tests to evaluate macros in child processes
bug 845918: Simplify run.js and refactor REPL out into its own module
bug 845918: Ensure numWorkers, workerConcurrency, and workerMaxJobs server settings are supported
bug 845918: Include the error call stack in macro execution error message
Merge pull request #27 from lmorchard/845918-macro-process-cluster

bug 845918: Switch to multi-process work queue for evaluating macros