Unify and beautify the code

There were some missing spaces.
Add try/catch-block for catching parse errors

JSON.parse-errors get catched now. The callback is called with the
error which occured during the parsing.
Unify error callbacks

new syntax: error, data received from the api, the full response, (only
for GET-endpoints) the url called (including the GET parameters)
Version 1.3.0

* Consistent coding style
* New error format: error, data (from Twitter; string), full response,
(only for GET endpoints) url with GET parameters
* JSON.parse errors get caught and returned through the callback.
(see error format above)