Updates to support high availability

Provides HA support, with security if needed. Updates to all applicable components have been made and additional components are now available:
* `cdh5.hadoop.standby` - the default standby NameNode (only one should be used)
* `cdh5.hadoop.journalnode` - JournalNodes (there should be a minimum of three of these)

Blueprints should:
* have one standard namenode host definition like you're used to
* have a single additional host definition with both `cdh5.hadoop.namenode` and `cdh5.hadoop.standby`. **This is very important**
* have at least three separate host definitions that provide `cdh5.hadoop.journalnode` (generally recommended to use NN, standby NN, and another)
* use proper ordering for HA orchestration:
 1. journal nodes first
 2. then NN and HANN with the same order index
 3. datanodes
 4. and so on

When using HA mode, instead of connecting to HDFS using a URI to a specific namenode, you should connect using the nameservice ID (hardcoded at this time to `default`). For example, `hadoop fs -ls hdfs://default/tmp` will properly determine the active namenode regardless of failover status. Where necessary, this has been updated in configuration (e.g, HBase)

Automatic failover is not supported, thus to start the failover process from the original NN (dubbed nn1) to the standby (nn2), as the hdfs user do `hdfs haadmin -failover nn1 nn2` and swap the order of the namenode IDs to reverse the status.