nex3/sass — pull request #374 by petebrowne (2012-05-02 13:03:28+00:00)
Title: Add null literal.

Modified pull request from #361 with suggested changes.

I've left string operations with `null`s as they were:

``` scss
selector {
property: 'foo' + null; // 'foo'
property: 'foo' - null; // 'foo-'
// etc...
}
```

But added a SyntaxError whenever a `null` is involved in other operations:

``` scss
selector {
property: null + 1; // Sass::SyntaxError
property: black / null; // Sass::SyntaxError
// etc...
}
```

Also, we discussed properties not printing when they have empty values. Currently, a SyntaxError is thrown in that case. Is there any reason to change from this?