Support only node >= 0.12.x and io.js

[apaprocki]

At some point in the (near?) future, I'd like to drop Node 0.6.x and 0.8.x support and focus on Node 0.10.x and 0.12.x (currently 0.11.x). If anyone has any objections or comments, this is the place to put them.

[ericvw]

Commandeering this issue to track progress for only supporting node >= 0.12.x and io.js.

[ericvw]

Branch node-v0.12 created to publicize progress.

[ericvw]

8887947 now puts the hard requirement on what is supported.

Going to create a milestone with some itemized issues that have been identified.

[ericvw]

Created milestone node >= 0.12.x and io.js >= 1.0.x with issues assigned.

[MichalStaruch]

Support for node.js 0.12.x will be dropped on December 2016 (see the Farewell to Node.js v5, Preparing for v7 article) and io.js was merged back to node.js in 2015 (since v4), so I think blpapi-node should provide full compatibility with node.js v4 and v6 (LTS and soon-to-be-LTS lines), instead.