Massive refactoring over chain API

 - now chain api is tend to be covered by tests
 - it's important to save backward compatibility
 - at thit moment tested only simple chain actions
Synchronous result and excaption raising from chain item are now supported
Choke event as data-is-over signal implemented

 - tests've been slightly refactored
 - middleman chain item tested with error generation. Now chain won't be interrupted if some error ocurred while chainline processing
Exeptions greedy feed fixed

 - now programmical errors won't be fed by chain exception processing code and redirected to errorbacks (and if noone awaits errors like AssertionError or TypeError - redirected to the event loop and be hidden forever)
Simple coroutine inline chain support
Intermediate chain coroutine without raising errors are now supported
Middleman coroutine processing improved

 - now inline chaining in coroutines must be finished if some error occurred in it
 - now coroutine can throw exceptions and it'll be correctly processed
 - also exceptions can come from `yield` statement
 - tests code templating done over Chain class
Synchronous API introduced

 - you can get chain result synchronous by invoking `get` method
 - if service is designed to send multiple chunks, it'll be correctly processed in the right order
 - exceptions rethrow implemented
 - also timeout can be specified. There are some value checks for it
 - of course, listed features are covered by tests
Wait method implemented for chains. It also can be tested for pending results

 - now result value keeping in `FutureResult` class can be reset, tested for null result, initialized with null result and exceptionally safe reset&get
Chain can now be used as generator (synchronous API)
Fixed bug when future was not unbound when needs
Code cleanup and prettifying

 - now framework has own testing package with submodules and concubines
 - ChokeEvent is now located in exceptions.py module
 - moving tests from inner package to outer directory, cause all of them are meant to be executable
Package decomposition

 - setup.py fixed
PEP-8 nazi
Code style. Absolute imports
Assert raise-error-check fix
Another pack of tests have been added
More verbosity while testing with mocks

 - removed deadline timeouts from tests
Old chain API replaced by new once

 - `ChainFactory` is now called just `Chain`
 - changed default behaviour `ServiceMock` class when no chunks provided - there will be only ChokeEvent emitted
 - log will be flushed on mocks assertion
 - another pack of tests have been written to check more yield-based usage of chain API
 - cocaine-tools cli module now can configure logging verbosity
Future class now explicitly send ChokeEvent exception

 - fixed situation when `Future.close()` is called earlier than `Future.bind()`