CLI + Blank project generator

[JedWatson]

As discussed in #25, I'm splitting this out into its own issue.

Would be valuable to have a cli (could be a yeoman generator to start with) that generates a blank touchstonejs project. The demo is great for examples, but then you have to rip everything out of it when you start building your app which isn't a great experience.

Workflow could be something like this:

$ touchstonejs new my-project

Welcome to TouchstoneJS! We'll create you a new project.
Which template would you like to use?
[x] Blank
[ ] Demo (see demo.touchstonejs.io)
[ ] ... more when we have other templates
Great, we'll create you a new Blank project.
Would you like to create a new directory? [Y/n] Y
Creating my-project...
(npm install)
(cordova install)
You're ready to start!
Type "cd my-project" then "touchstonejs start" to run the development server.
Type "touchstonejs help" for more info, including how to build and deploy your app.