Search: Allow to specify script fields to be loaded

[kimchy]

Script fields are basically scripts that a evaluated and returned per hit, two nice benefits is the fact that the field does not have to be stored, and a custom value can be returned (note, they probably make sense on numeric fields and on not analyzed fields).

A sample:

{
    "query" : {
        ...
    },
    "script_fields" : {
        "test1" : {
            "script" : "doc['my_field_name'].value * 2"
        },
        "test2" : {
            "script" : "doc['my_field_name'].value * factor",
            "params" : {
                "factor"  : 2.0
            }
        }
    }
}

[kimchy]

Search: Allow to specify script fields to be loaded, closed by 0a1bc87.