Beats 1.0.0-beta4: lightweight log forwarding with Filebeat

Beats version 1.0.0-beta4 introduces Filebeat, a new open-source log forwarder designed to efficiently transfer logs to Logstash or Elasticsearch, building on the Logstash Forwarder code base but with notable improvements. Filebeat aims to provide lightweight log forwarding with no dependencies, ensuring that no log lines are lost during network disruptions by using an "at-least-once" delivery approach, though this can result in duplicate messages. The new protocol includes enhancements like encryption, message batching, and a slow start mechanism to minimize duplicates. Filebeat supports Windows, addressing previous limitations, and uses YAML for configuration to facilitate migration from Logstash Forwarder, with an extensive guide available to assist users. While Filebeat was the focus, improvements were also made to Packetbeat and Topbeat, enabling data transfer to Logstash without Redis. Future updates plan to include features like multi-line support and Windows event log integration, aiming for a general availability release soon.