Add CSSLint setup included in grunt-css

- Removed spacing around media query which the parser has issues with
and doesn't appear to match the W3C grammar.
- Outstanding issue with the @-moz-document usage causes an error (https://github.com/nzakas/parser-lib/issues/53), so I didn't add it to the default testing call
- Excluded all failing rules to start, as they can be opted in and fixed progressively (ex: turn on `zero-units` after #5594 is merged)