Zookeeper init script status, force-stop and force-reload commands are broken

http://getsatisfaction.com/cloudera/topics/zookeeper_init_script_status_force_stop_and_force_reload_commands_are_broken_in_cdh3_on_debian_ubuntu

There are two issues causing the status, force-stop and force-reload commands to fail in the Zookeeper init script (/etc/init.d/hadoop-zookeeper-server) from the hadoop-zookeeper-server package:

1) The PID_FILE variable is set to /var/run/zookeeper/zookeeper_server.pid when it should be /var/run/zookeeper/zookeeper-server.pid

2) The hadoop_is_process_alive function is missing, copying a variant from the hadoop init scripts fixes this issue.