Support UNIX domain socket server for ad-hoc annotation queries

[stephen-soltesz]

Today, uuid-annotator exports annotations for events received from tcp-info.

For services like traceroute-caller, where additional IPs are collected, the uuid-annotator should support a local API for making additional annotation requests.

The API should be served over unix domain sockets (like tcp-info) to prevent spurious local TCP communications.

[pboothe]

#23 #24

[pboothe]

API is still not what users would prefer - a bulk tagging has been requested, where instead of asking for the decoration of a single IP, an array of IPs can be passed in