1. Split library in two modules to allow custom implementations.
2. Use [Guice](https://github.com/google/guice) for dependency injection.
3. Use [Jackson](https://github.com/FasterXML/jackson) for json (de)serialization.
4. Added extra validation to methods before performing requests.
5. BotOptions has been renamed ot DefaultBotOptions. It allows now to set number of threads for async methods execution and the complete `RequestConfig` for customization purpose.
6. Added convenient method for `setChatId` using just a `Long` value instead of an String.
7. In `SentCallback` method `onError` changed second parameter to `TelegramApiRequestException` and `onResult` now receives the deserialized answer (of type `T`) instead of a `JSONObject` as second parameter
