Updated dependencies to support io.js

[ngoossens]

Updated the dependencies (nan & node-arraybuffer [https://github.com/vmolsa/node-arraybuffer/pull/1]) to support building using io.js 2.

Please review.

[zbjornson]

Seems this is also necessary for node 0.12.x. Works for me with that engine.

[ThomWright]

@dcodeIO Any chance you could merge this?

[zbjornson]

@ThomWright if you're using a version of node that has Buffers backed by TypedArrays (e.g. 4.0 and later), you can just access the underlying buffer with Buffer.buffer and make a new array view on that. But, this module is necessary for earlier versions. (Some discussion here.)

[ThomWright]

Thanks, but I'm actually running in the browser (using Browserify), and I was hoping to use this library, but the installation fails trying to install memcpy (npm 3.3.4, node 4.1.0).