Seperating Chukwa Metrics collection from Hadoop Metrics collection

Chukwa Metrics are the same format as HadoopMetrics, therefore it is possible to collect chukwa metrics parsed by HadoopMetricsProcessor. However, HadoopMetricsProcessor would try to store Chukwa metrics to Hadoop HBase table. This ticket is to make separation of the two metrics types properly in the configuration files.