Update Node.js to the latest version

`npm 1.4.23` that [goes with](https://raw.githubusercontent.com/joyent/node/v0.10.31/ChangeLog) `node 0.10.31` is not available to download separately, but does come bundled with the MSI version.

While testing that, I found that global modules are not available for use because they're installed in  `%appdata%\Roaming\npm` by default, due to the bundled `npmrc` file. The `postinstall` script removes that file, so global modules get installed inside scoop's nodejs directory, thus making them usable.

I tested on my Windows 8.1 x64 machine. I don't have a 32-bit machine to test on, but I imagine (hope?) it's the same.