api: Implement bucket notification. (#2271)

* Implement basic S3 notifications through queues

Supports multiple queues and three basic queue types:

1. NilQueue -- messages don't get sent anywhere
2. LogQueue -- messages get logged
3. AmqpQueue -- messages are sent to an AMQP queue

* api: Implement bucket notification.

Supports two different queue types

- AMQP
- ElasticSearch.

* Add support for redis

vendor/gopkg.in/olivere/elastic.v3/search_queries_geo_polygon.go

@@ -0,0 +1,72 @@
+// Copyright 2012-2015 Oliver Eilhard. All rights reserved.
+// Use of this source code is governed by a MIT-license.
+// See http://olivere.mit-license.org/license.txt for details.
+
+package elastic
+
+// GeoPolygonQuery allows to include hits that only fall within a polygon of points.
+//
+// For more details, see:
+// https://www.elastic.co/guide/en/elasticsearch/reference/current/query-dsl-geo-polygon-query.html
+type GeoPolygonQuery struct {
+	name      string
+	points    []*GeoPoint
+	queryName string
+}
+
+// NewGeoPolygonQuery creates and initializes a new GeoPolygonQuery.
+func NewGeoPolygonQuery(name string) *GeoPolygonQuery {
+	return &GeoPolygonQuery{
+		name:   name,
+		points: make([]*GeoPoint, 0),
+	}
+}
+
+// AddPoint adds a point from latitude and longitude.
+func (q *GeoPolygonQuery) AddPoint(lat, lon float64) *GeoPolygonQuery {
+	q.points = append(q.points, GeoPointFromLatLon(lat, lon))
+	return q
+}
+
+// AddGeoPoint adds a GeoPoint.
+func (q *GeoPolygonQuery) AddGeoPoint(point *GeoPoint) *GeoPolygonQuery {
+	q.points = append(q.points, point)
+	return q
+}
+
+func (q *GeoPolygonQuery) QueryName(queryName string) *GeoPolygonQuery {
+	q.queryName = queryName
+	return q
+}
+
+// Source returns JSON for the function score query.
+func (q *GeoPolygonQuery) Source() (interface{}, error) {
+	// "geo_polygon" : {
+	//  	"person.location" : {
+	//         "points" : [
+	//             {"lat" : 40, "lon" : -70},
+	//             {"lat" : 30, "lon" : -80},
+	//             {"lat" : 20, "lon" : -90}
+	//         ]
+	//     }
+	// }
+	source := make(map[string]interface{})
+
+	params := make(map[string]interface{})
+	source["geo_polygon"] = params
+
+	polygon := make(map[string]interface{})
+	params[q.name] = polygon
+
+	points := make([]interface{}, 0)
+	for _, point := range q.points {
+		points = append(points, point.Source())
+	}
+	polygon["points"] = points
+
+	if q.queryName != "" {
+		params["_name"] = q.queryName
+	}
+
+	return source, nil
+}