Rabbit-client

**changelog**
- added [error strategies](http://rabbit-client.amenezes.net/docs/7.-error_strategies/) to publish events in the DLX

**changelog**
- concurrent task execution;
- automatic qos configuration;
- automatic Dead Letter Exchange configuration and use.

**changelog**
- SQL queries migrated to SQLAlchemy ORM.
- Now event table supports multiple database as backend.

**changelog**

- added [polling-publisher](https://rabbit-client.amenezes.net/docs/2.-polling-publisher/) feature;
- new documentation powered by [portray](https://github.com/timothycrosley/portray);
- now there are two methods for connect on rabbitmq:
- `persistent_connect` (with reconnect feature)
- `connect` (simple connect without reconnect feature)

First public release.