 Not able to resolve references whose keys may contain '/'

Hi
i am not able to resolve references whose keys may contain '/'

for example 

```
a.json
{
 car : {
"$ref" : "car.json#/~1car"
}
}

car.json
{
 "/car" : {
"color" : "white"
}
}
```

To see how '/' are encoded and used in ref tokens please see this 
https://tools.ietf.org/html/rfc6901
