"libraries" property in targets.json

[kevwilde]

Some targets could require specific libraries that should be added to targets.json:

I suggest the following syntax:

{
    "microsoft" : {
        "metro": {
            "dedicatedResources": "metro",
            "libraries": [
                {
                    "name": "Metro", 
                    "refs": ["*"]
                }
            ]
        }
    }
}