Facets: Script Histogram facet

[kimchy]

Allow to specify scripts for both key and value in histogram facets. For example:

{
    query : {
        "match_all" : {}
    },
    facets : {
        "histo1" : {
            "histogram" : {
                "key_script" : "doc['date'].date.minuteOfHour",
                "value_script" : "doc['num1']"
            }
        }
    }
}

interval can also be specified, which will further normalize the key value into buckets (by default, if its not set, the actual key value will be used). Also, params can be specified to the scripts.

[kimchy]

Facets: Script Histogram facet, closed by 2d6f61b.