Added SCSS support

I saw your post on Reddit and really wanted to use Brew, but I'm a sass guy. I actually built a Sass Bootstrap 3 Wordpress theme with Bones last week, but yours is definitely more thorough. So I kept everything you have, just added sass support.

For my edits: 
- Used the .scss files in /scss from the Bones theme
- Used Bootstrap files in /scss/bootstrap from Sass-Bootstrap(https://github.com/jlong/sass-bootstrap) 
- Translated your custom .less files into .scss syntax by hand

I compiled all the SCSS and it's working perfectly. 

(Also, I removed some import statements in ie.less that were trying to import non-existent files)

Thanks for your work on building this! I'll be using this as a starter for all of my projects. You rock.