fixed zookeeper module to work with cdh4

(tested on CentOS6)
- package name was wrong for cdh4.
- /etc/defaults/zookeeper not present in cdh4. therefore removed JMX_PORT variable throughout. Its not possible to manage this for zookeeper afaik.

Usage:
- Make sure CDH4 repo is installed
- On your zookeeper server(s):

class {'zookeeper':
    hosts       => { 'i-can-has.zoo.com' => 1, },
}

include zookeeper::server