Change hbase script to not add /etc/zookeeper

Currently, /etc/zookeeper is included in the hbase classpath. Because of this, we may sometimes have the zoo.cfg file undesirably override settings.

For example, if we
export HADOOP_CLASSPATH=`hbase classpath`
and run a HBase cluster-to-cluster CopyTable from the command line, we see that CopyTable gets the zoo.cfg settings even after specifying the destination zookeeper client. The CopyTable job ends up copying the table from the source back to the source.

A fix to this is:
1) Remove /etc/zookeeper from /usr/bin/hbase so zoo.cfg is not in the hbase classpath
2) Add all the properties from zoo.cfg into hbase-site.xml

Documentation needs to be changed to tell users to use hbase-site.xml for zookeeper configuration.