Should not add setter to Array expression values in v-with (breaks in IE & Safari)

having 

``` html
<div v-with="points: [{x:1003, y:666}, {x:995, y:680}]></div>
```

will warn in Chrome:

```
Invalid setter function body:  [{x:1003, y:666},{x:995, y:680}]"
```

and break in IE: "Invalid left-hand side in assignment"
