Portability change.

 - using builtin function `zip` instead of `izip` makes code more portable with python 3.
 - tiny styling done.
Protocol messages renaming.
Code cleaning over protocol messages.
Fix attribute mismatch.
Fixed bug with worker type mismatch.

 - on termination, worker died because an internal exception raised.
Protocol message review.

 - Drop metaclass definition in favor on usual initialization method.
Drop unused file.
Logger has been slightly refactored.

 - convergence of style done for logger protocol definition.
Logging system has been revamped.

 - There is no more Logger singleton class. Instead of this we have logger service, for which you can create as many instances as you wish.
 - Instead of direct logger manipulating, you should use special CocaineHandler for default Python logging module. It will use own pool of Loggers (singleton at this moment, yes).
 - Various 'colored' stuff moved to the cocaine-tools.
 - Examples updated.
Reflection for protocol message class added.

 - it can now display itself as string.
Core logger renamed. Do not rename it to `cocaine` again.

 - Cause it lead to the implicit patching inside `logging` module. All log handlers having root package `cocaine` will be patched to use CocaineHandler, which will lead to the infinite recursion, because `Logger` service tries to log (debug, obvious) via itself.
Worker class has been completely refactored.

 - Class and functional decomposition done - now every worker has own health- and connection-control system.
 - HealthManager is responsible for managing worker heartbeats and disowns.
 - WorkerConnection incapsulates communication between worker and socket (or maybe something else?) streams.
 - Pretty debug logging added.
Quotes nazi.
Let the old code die.
Resolved circular imports in logging packages.
Example and benchmarks updated.
Error representation changed for echo example.
Functional decomposition done for worker.