Merge tag 'v0.2.1'

v0.2.1
server: add an address() method for port or path
server: add an unref() method
Merge pull request #4 from strongloop/feature/extra-methods

Feature/extra methods
cluster: refactor ipc protocol from cluster

lib/message now encapsulates the request/response message protocol, and
lib/cluster attaches it to a node cluster.
process: support parent/child request/response
Merge pull request #5 from strongloop/feature/node-ipc-channel
v0.2.2
Merge branch 'release/0.2.2' into production