Added "&tz=<TIMEZONE>" paramter to tsdb url
Added "&tz=<TIMEZONE>" paramter to tsdb url

This should make easy to understand graphs in different timezones
 - Note: tz values are not verifed.
 - TIMEZONE: Any valid Java timezone ID: PST, UTC, CST, Asia/Kathmandu etc

OpenTSDB/opentsdb,MadDogTechnology/opentsdb,eswdd/opentsdb,alienth/opentsdb,alienth/opentsdb,MadDogTechnology/opentsdb,johann8384/opentsdb,OpenTSDB/opentsdb,OpenTSDB/opentsdb,eswdd/opentsdb,MadDogTechnology/opentsdb,johann8384/opentsdb