- remove no-longer-needed libgrok/dependencies documentation.
- remove no-longer-needed libgrok/dependencies documentation.

Aloomaio/logstash-kafka,Aloomaio/logstash-kafka,opentable/logstash-kafka,joekiller/logstash-kafka,joekiller/logstash-kafka,opentable/logstash-kafka,tinglinux/logstash-kafka,tinglinux/logstash-kafka