Add CSSLint and `grunt test` task to lint CSS in the src/ dir

This gives basic linting of src CSS, but ignores linting normalize.css.
Make minor tweaks to CSS files to clear basic linting issues
add /*csslint */ ignores
Merge pull request #1 from tilomitra/csslint

add /*csslint */ ignores
Add TODO comments to the CSSLint overrides which we should remove
Merge pull request #65 from ericf/csslint

Add CSSLint and `grunt test` task to lint CSS in the src/ dir