fixed buggy default log.dirs. now it:  - is broker-id specific, i.e. /log/$id to be able to launch N brokers in one executor  - could be overriden via --options
fixed buggy default log.dirs. now it:
 - is broker-id specific, i.e. /log/$id to be able to launch N brokers in one executor
 - could be overriden via --options

vidhyaarvind/kafka-mesos,asteris-llc/kafka,mesosphere/kafka,tnachen/mesos-kafka,yonglehou/kafka-1,advertine/kafka,tc-dc/kafka-mesos,smorin/kafka,yonglehou/kafka-1,smorin/kafka,sujeetv/kafka,tc-dc/kafka-mesos,serejja/kafka,advertine/kafka,tnachen/mesos-kafka,vidhyaarvind/kafka-mesos,sujeetv/kafka,Banno/kafka,Banno/kafka,mesosphere/kafka,asteris-llc/kafka,tc-dc/kafka-mesos,serejja/kafka