Upgrades the HDP plug-in to install Hue

Adds a HUE service definition to the set of defined services.  This service
  contains a HUE component defined to be a CLIENT allowing a single instance
  to be configured within a cluster.
Adds the following configuration groups to the set of defined configurations:
  hue-ini - contains configuration options used to build the hue.ini file to
            be deployed to the Hue node
  hue-core-site - contains parameters to add or update within the
                  core-site.xml file to be deployed on relevant nodes
  hue-hdfs-site - contains parameters to add or update within the
                  hdfs-site.xml file to be deployed on relevant nodes
  hue-webhcat-site - contains parameters to add or update within the
                     webhcat-site.xml file to be deployed on relevant nodes
  hue-oozie-site - contains parameters to add or update within the
                   oozie-site.xml file to be deployed on relevant nodes
Adds the HueService class to the set of Service classes. This class implements
  Service to validate that the required services are to be installed in the
  cluster (HIVE, OOZIE, WENHCHAT), ensure the required components are
  installed on the Hue node (HIVE_CLIENT), update relevant site configuration
  files (see above), generate a hue.ini file, install and configure Hue on the
  specified node
Updates the base Service class to include a new property - ambari_managed.
  This property is a Boolean value declaring whether a service is managed by
  Amberi (True) or not (False). The default value is True, since most services
  in the HDP are managed by Ambari. Ambari, Hue, and possibly services to be
  added in the future are not; thus this property is used to generalize logic
  in the HDP plug-in.

Implements: blueprint hdp-plugin-hue-support

Change-Id: Id3ff7a18aa1f65a733c637dc2ea4ce8f988165e4
Merge "Upgrades the HDP plug-in to install Hue"