Zabbix MySQL replication bridge for item metrics.

Notable discussion: [highspeed, high metric count collectors and tcollector](https://groups.google.com/forum/#!topic/opentsdb/22Q37JFwcTo)

![chart2](https://cloud.githubusercontent.com/assets/65640/3872024/67f21284-210d-11e4-9590-3aebecba3592.png)
![chart2_q_opentsdb](https://cloud.githubusercontent.com/assets/65640/3872023/67f1c6b2-210d-11e4-925f-cf40c0275bb3.png)