Support for 'interval' filter.

[var23rav]

Is there any 'Interval Filter' available ?

I couldn't find it in "type" : "interval" in filter code.

Filtering on a set of ISO 8601 intervals:

{
    "type" : "interval",
    "dimension" : "__time",
    "intervals" : [
      "2014-10-01T00:00:00.000Z/2014-10-07T00:00:00.000Z",
      "2014-11-15T00:00:00.000Z/2014-11-16T00:00:00.000Z"
    ]
}

[gianm]

@var23rav, it's probably missing. A PR would be welcome!

[var23rav]

Initiated a PR #87

[var23rav]

Closing since feature is available with PR 87 code merged.