Fixes #19
Fixed issue [#19](https://github.com/larsonjj/generator-yeogurt/issues/19)
* Updated file structure so that all dashboard files stay within the `dashboard/` folder (was confusing before when dashboard files would be at the root level)
* Added [grunt-uncss](https://github.com/addyosmani/grunt-uncss) task when using Vanilla CSS, so unused CSS will be removed during builds (big boost in performance)
* Cleaned up prompts a bit. Removed miniscule options (ex. adding IE11 icons or adding apple homescreen options: these are now included in the HTML5 Boilerplate extras option)
* Added a `grunt serve:dist` task, so now it will be easier to see your builds running on a local server.
Added info on grunt-uncss