Adding support for JSON values.

Hi,

Congratulations for your work for me was very useful, now i give my contributes:
I extend your functions _parseValue adding support for list, hash or multidimensional array whit json object structure.
NOTE: if value start with json array maybe return an array with random string depend on comma separate but if a json object work very nice!
* Note: if you replace your parse [] with the default json_decode it might be possible to cover even if the value starts with [and ends with] and both the {} but I like your syntax to write the array in your way and I  preferred to propose this solution! because if I want to write an array json I need to use json {"array": [1,3,4,5,6,7,8]} so do not sacrifice any functionality!

Example data : @MenuData {"root":{"child":{"arraychild":[0,1,2,3]}}, "arraysroot" : [1,2,3]}
Output: 
```php                         
                        [menudata] => stdClass Object
                                (
                                    [root] => stdClass Object
                                        (
                                            [child] => stdClass Object
                                                (
                                                    [arraychild] => Array
                                                        (
                                                            [0] => 0
                                                            [1] => 1
                                                            [2] => 2
                                                            [3] => 3
                                                        )
                                                )
                                        )
                                    [arraysroot] => Array
                                        (
                                            [0] => 1
                                            [1] => 2
                                            [2] => 3
                                        )
                                )
```