Merge pull request #402 from chinmay-gupte/chinmay/add_per_gran_capability_to_getMetricsState_JMX_method

Add per gran argument to getMetricsState method of RollupServiceMBean
Fix the max queue size metric in Instrumented TPE
Refactor getMetricsState method into separate context MBean, so that it can be used even with RollupService turned off
Actually the ContextMBean interface
Merge pull request #403 from chinmay-gupte/chinmay/fix_the_max_queue_size_in_itpe

Fix the max queue size metric in Instrumented TPE
Merge pull request #404 from chinmay-gupte/chinmay/expose_metrics_state_on_ingestion_context

Refactor getMetricsState method from RollupServiceMBean into a separate ContextMBean interface
Merge branch 'master' into rax-stage

* master:
  Actually the ContextMBean interface
  Refactor getMetricsState method into separate context MBean, so that it can be used even with RollupService turned off
  Fix the max queue size metric in Instrumented TPE