Fix test op for object equality and order #39

### Performances:

Running json-patch.html test on Chrome 33.0.1750.152 on Intel Mac OS X 10_9_3

#### no additional tests:

##### before
```should Test Operation	433545 ops/sec```

##### after
```should Test Operation	556552 ops/sec``

#### with additional tests (except test L:67)

##### before:
```should Test Operation	431203 ops/sec```

##### after:
```should Test Operation	590440 ops/sec```
damn IE8 :-1: 

Maybe a separate file should be provided with Object.keys and Object.observe polyfill so you don't have to load the code if you don't want to?