Send asset folder path to a javascript of a widget

Comparing #4 with #5

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Now, in your script1.js, you can use the variable assetUrl. For example, if you do alert(assetUrl); you'll see the path of this assets, ıe. '/assets/234hn43/'.

##Important
To do this in more widgets or extensions, use unique javascript var name like
<[extensionName>]AssetUrl.