lumberjack handler integration

[agalera]

the idea is to support the lumberjack protocol (https://github.com/elastic/logstash-forwarder/blob/master/PROTOCOL.md) to insert logs in a simple way, this protocol is the one used by logstash, which will allow to send logs with the logstash library to easylogs

TODOs

• basic implementation
• move lumberjack server to correct folder
• fix import models
• SSL implementation (the code is commented but you should be able to configure it)
• add new service in docker-compose and expose port 5544
• add a client example

IMPROVEMENTs

• inserts are done one by one, a buffer should be created and insert in bulk