Let file attributes include objects and arrays

Currently, a file's attribute can consist of strings or Int32. Allow for objects and arrays to be included, i.e. { "link": "", "type": "", "title": "names-and-numbers", "statusCode": 0, "attr": { "name string": "John", "favorite_number int32": 4, "friends_and_numbers obj": { "James int32": 10, "Bob int32": 92 } } } or { "link": "", "type": "", "title": "names-and-friends", "statusCode": 0, "attr": { "name string": "John", "number_of_friends int32": 4, "friends arr": ["James", "Bob", "Sarah", "Jessica"] } }