Adding collector for mysql throughput using pt-tcp-model

See http://www.percona.com/doc/percona-toolkit/2.1/pt-tcp-model.html
for info about analysis that this collector is doing.
adding hbase table/region usage collector

This is a collector that was inspired by the mysql_throughput collector.
It provides a little bit of insight into hot tables and regions in hbase
for clusters that don't have access to these metrics (e.g. pre-CDH4)