anchor.diff:    during concurrent logging {pull}650[650]
   - Reduce memory usage by having separate queue sizes for single events and bulk events. {pull}649[649] {issue}516[516]
   - Set default bulk_max_size value to 2048 {pull}628[628]
  +- Fix logstash window size of 1 not increasing. {pull}598[598]
   
   *Packetbeat*
   
  
positive.code: ==== Bugfixes
  
  *Affecting all Beats*
  - Fix logstash window size of 1 not increasing. {pull}598[598]
  
  *Packetbeat*
  
  
negative.code: *Affecting all Beats*
  
  - Make logstash output compression level configurable. {pull}630[630]
  - Some publisher options refactoring in libbeat {pull}684[684]
  - Move event preprocessor applying GeoIP to packetbeat {pull}772[772]
  
  *Packetbeat*
  
  