Fully reworked binding. Is breaking to previous versions.
- Response resolvers reimplemented (no while loops with responses);
- Generators removed, callbacks added.
Each callback receives `response_data`, `response_type`, `loop` arguments.
`loop` argument is not none only when working with `asyncio`;
- Request params and responses are objects of core `types` now.
See https://github.com/tonlabs/TON-SDK/tree/master/docs and `tonclient.types` for more info;
- Methods' docstrings updated;
- Tests updated.