Support property keys in AMDJS filter

Current AMDJS filter does not parse/produce resource keys other than string literal.

For example,

```
define({
  "strkey1" : "value 1",
  prop2 : "value 2",
  3 : "value 3" 
});
```

In the example above, only the k-v pair "strkey1" : "value 1" is recognized.