Update: multilayer support

Update: multiple layers are now supported

The function was tested with following example from Wikipedia/JSON

{
  "firstName": "John",
  "lastName": "Smith",
  "isAlive": true,
  "age": 27,
  "address": {
    "streetAddress": "21 2nd Street",
    "city": "New York",
    "state": "NY",
    "postalCode": "10021-3100"
  },
  "phoneNumbers": [
    {
      "type": "home",
      "number": "212 555-1234"
    },
    {
      "type": "office",
      "number": "646 555-4567"
    }
  ],
  "children": [],
  "spouse": null
}

simple_JsonDecode_v1.1

Fixing of the varargin issue (the function only worked with the UI call) and a example json-file was provided.
Many thanks @thrynae for issueing the bug-report!

simple_JsonDecode_v1.0.1

Initial release version 1.0.1 (including minor updates)