deepEqual doesn't work on Maps or Sets

```
var nodeunit = require('nodeunit');
nodeunit.assert.deepEqual(new Map([[1,2]]), new Map([[3,4]]));
// expected: exception
nodeunit.assert.deepEqual(new Set([1]), new Set([2]));
// expected: exception
```

Start at the nodeunit.assert.deepEqual entry point and locate the existing tests for deep equality. Reproduce the Map and Set examples from this issue, then add coverage so unequal collections are rejected while matching collections retain the expected behavior.

Vom Indexierungsmodell aus dem Issue-Text verfasst.