[signature changes]
* Fluent\Logger\FluentLogger::__construct($host, $port);
  removed tag parameter as that too much.

* Fluent\Logger\Logger::post($tag, array $data)
  add tag parameter. and remove additional tag.

[add]
* Fluent\Logger\Entity
  entity is a log message. now you can send entity directly with post2 method.
  this change makes easy error handling.
  basically, you don't have to create entity your self.

* Fluent\Logger\Logger::post2(Fluent\Logger\Entity $entity)

* Fluent\Logger\PackerInterface

* improve error handling
  for now, you can register your error handler to logger instance.
  you can store, re-send entity here.
  maybe error handling signature will be change near the future but it's really useful.

[modified]
* Fluent\Logger\FluentLogger::open
  re-use instance with specified parameters.

[others]
many improvmemnts.