Fix for issue #294 and other clean-ups related to ZK installation

Changes in prep for ZK rolling restart implementation include:
- Fix for issue #294.
- Changes for enhancement #309 
- Changes to prevent manual change to the zookeeper data directory by an admin. But changing the data directory through chef attributes will not be stopped since the directory gets created in chef recipe before ZK gets start.
- Stop [ZK init](https://github.com/bloomberg/chef-bcpc/blob/4c4ba33f0106468f287470e29e624be3b163326c/cookbooks/bcpc-hadoop/recipes/zookeeper_server.rb#L53-L56) and [update-alternatives](https://github.com/bloomberg/chef-bcpc/blob/4c4ba33f0106468f287470e29e624be3b163326c/cookbooks/bcpc-hadoop/recipes/zookeeper_config.rb#L12-L17) resources after the first run. 
This will get stored in /etc/default/zookeeper-server and used by zookeeper-server process.