Issues parsing multidimensional array arguments

Multidimensional arrays are not parsed correctly,
```
> JSON.stringify(url('?','?t[0][0]=x'));
"{"t[0]":["x"]}"
> JSON.stringify(url('?','?t[0][0]=x&t[1][0]=y'));
"{"t[0]":["x"],"t[1]":["y"]}"
```

The expected behavior is as follows,
```
> JSON.stringify(url('?','?t[0][0]=x'));
"{"t":[["x"]]}"
> JSON.stringify(url('?','?t[0][0]=x&t[1][0]=y'));
"{"t":[["x"],["y"]]}"
```
