cmd/scollector: Fix hw.chassis.temps* metrics
cmd/bosun: Add the d() func, i.e. d("1h")

d() returns the number of seconds for that opentsdb duration string. Currently this will just be nice when doing things like forecastlr(q("avg:6h-avg:os.disk.fs.percent_free{$filter}", "7d", ""), 0) / 60 / 60 / 24 or using the since function. However, we might consider changing the arguments to query functions to be scalars and use this function.
Merge pull request #598 from bosun-monitor/dell_hw

Fixes #593 hw.chassis.temps* metrics
Merge pull request #599 from bosun-monitor/duration_func

cmd/bosun: Add the d() func, i.e. d("1h")
cmd/scollector: Collect a new metric linux.disk.bytes

This will allow us to see bytes per second being written/read to a disk. We currently don't have this, we have sectors per second - but the size of the sector is unknown.
Merge pull request #602 from bosun-monitor/linux.disk.bytes

cmd/scollector: Collect a new metric linux.disk.bytes
cmd/bosun: Add HTTPGet func

HTTPGet takes a url and returns the raw text from the url. If there is any error, it returns that error as text.
Merge pull request #601 from bosun-monitor/template_http_get

cmd/bosun: Add HTTPGet func
cmd/bosun: Add tag list support to expressions