Add version to packed and unpack data objects.

Switch data to {version:'2014e',zones:[],links:[]} format instead of just an array of zones.
Build latest data and add a hook to get the latest version identifier.
Build latest data
Compiling data/{packed,unpacked}/2014{a..e}.json
Add `moment.tz.load` to import data in the {version:'2014e',zones:[],links:[]} format.

#94
Use `moment.tz.load` instead of `moment.tz.add` to import initial data in Node.

#94