registerClientScript() does not depend from Alias

I had an issue with yiinfinite-scroll using popular Yii setup like:

````
/
    backend/
    common/
        ...
        extensions/
            yiinfinite-scroll
            ...
    console/
        ...
    frontend/
        ...
````

Calling widget inside frontend app will create "The asset to be published does not exist" fatal error.

I've updated registerClientScript() to fix this issue.