[TIMOB-18115] CLI: Drop support for Node.js 0.8

We need to drop support for Node.js 0.8. There are a number of Node dependencies that no longer support it and so we can no longer support it. Dropping support includes: * Updating the "engine" version in the package.json of both the Titanium CLI and node-appc. * Update the Titanium CLI Node.js version enforcement: https://github.com/appcelerator/titanium/blob/master/lib/titanium.js#L29-L37 * Publish a new version of node-appc * Update Titanium CLI's node-appc version * Publish a new version of Titanium CLI NOTE: As soon as node-appc has been updated, you can rev it and publish it.