Optionally run multiple ZooKeeper nodes

[ctubbsii]

It would be nice to be able to run multiple ZK nodes for testing on a single uno instance (different ports).

[ctubbsii]

I did this in a local branch manually. The steps needed are:

• Provision separate install directories for n zookeeper instances
• Provision separate data directories, each with a unique myid
• Provision separate log directories
• Modify zookeeper config template to account for different ports and different data directories, and to add references to peers
• Modify accumulo config template; need to add g on the end of the sed command in impl/setup-accumulo.sh which replaces UNO_HOST