tgh0831

# Loads data from OpenTSDB.
#
#   `server.url`: The URL of the OpenTSDB server (e.g. 'http://tsdb.example.com')
#   `metrics`: List of strings specifying the metrics to pull (e.g.
#       c("avg:web.cpu.user{host=*}", "sum:web.requests{type=login}")
#   )
#   `start.dt`: How far to go back in the time series, in any format OpenTSDB
#       (e.g. "4h-ago")
#   `end.dt`: Where to end the results (defaults to now)
#   `datify`: Whether to convert timestamps to POSIXlt objects (defaults to TRUE)