Version 0.0.60

* Added optional/safe module loader impress.require(moduleName)
* Added ZeroMQ support (optional/plugin)
* Improved impress.cluster.js with ZeroMQ pub/sub and req/rep
connections
* Added SSE cross-cluster retranlation over ZeroMQ
* Added npm programmatically API (optional/plugin) for future use in
web-based setup utility
* Moved GeoIP to optional/plugin
Version 0.0.60

package.json fixes