Correctly trim strings for css properties

This PR correctly trims property strings if passed in with a space. It also correctly matches unit less properties if the name is passed in as a 'string' and not camelCase by converting the string to camelCase.

* If a unit less value is passed with a space it'll return `1 px`
* ~~If passed 'z-index': 1 it'll return 'z-index': '1px' convert str camelCase when doin unitless lookup~~

See [test case]()

Not applicable anymore see #1662 

```js
var Hello = React.createClass({
    render: function() {
        var styles = {
            'z-index': 1,
            margin: '10 '
        };
        return <div style={styles}>Hello {this.props.name}</div>;
    }
});
```

~~The following component yields inline styles: `z-index:1px;margin:10 px;`~~