Allowed to pass custom command line arguments
pass a few more arguments down to sass

I've added `unixNewlines`, `precision`, and `cacheLocation`

`precision` is especially important for folks who use twitter
bootstrap as precision needs to be set to 10, but the default
is 5.
Replace quickTemp with broccoli-writer

Inspired by this change:
https://github.com/joliss/broccoli-sass/commit/a1c305f473e631af1b60ef4925f8e55d25910e15
add README file

Obviously most of the work for this was done by @joliss, so she gets the
credit.

I think the main part missing from this is how to use the options that
were added to ease interaction with ruby, such as bundleExec, loadPath,
and require
Replace quickTemp with broccoli-caching-writer.

Fixes #4.
Update package.json

Changed broccoli-static-compiler version
Added sass globbing
Fix sass-globbing
Fixed an error when spawning the globbed sass compilation
Fix mkdirp
Problem was fixed in wrong place.
Merge branch 'pr/1'
Merge branch 'pr/5'
Merge branch 'pr/6'
Merge branch 'pr/7'

Conflicts:
	index.js
Merge branch 'pr/8'

Conflicts:
	index.js
	package.json
Merge branch 'pr/9'

Conflicts:
	package.json