Stasis-HTTP: Flesh out bridge-related capabilities

This adds support for Stasis applications to receive bridge-related
messages when the application shows interest in a given bridge.

To supplement this work and test it, this also adds support for the
following bridge-related Stasis-HTTP functionality:
* GET stasis/bridges
* GET stasis/bridges/{bridgeId}
* POST stasis/bridges
* DELETE stasis/bridges/{bridgeId}
* POST stasis/bridges/{bridgeId}/addChannel
* POST stasis/bridges/{bridgeId}/removeChannel

Review: https://reviewboard.asterisk.org/r/2572/
(closes issue ASTERISK-21711)
(closes issue ASTERISK-21621)
(closes issue ASTERISK-21622)
(closes issue ASTERISK-21623)
(closes issue ASTERISK-21624)
(closes issue ASTERISK-21625)
(closes issue ASTERISK-21626)


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@391199 65c4cc65-6c06-0410-ace0-fbb531ad65f3

rest-api/api-docs/bridges.json

@@ -66,7 +66,7 @@
 				},
 				{
 					"httpMethod": "DELETE",
-					"summary": "Shut down a bridge bridge.",
+					"summary": "Shut down a bridge.",
 					"notes": "If any channels are in this bridge, they will be removed and resume whatever they were doing beforehand.",
 					"nickname": "deleteBridge",
 					"responseClass": "void",

rest-api/api-docs/events.json

@@ -56,6 +56,7 @@
 				"application_replaced": { "type": "ApplicationReplaced" },
 				"bridge_created": { "type": "BridgeCreated" },
 				"bridge_destroyed": { "type": "BridgeDestroyed" },
+				"bridge_merged": { "type": "BridgeMerged" },
 				"channel_created": { "type": "ChannelCreated" },
 				"channel_destroyed": { "type": "ChannelDestroyed" },
 				"channel_snapshot": { "type": "ChannelSnapshot" },
@@ -127,6 +128,20 @@
 				}
 			}
 		},
+		"BridgeMerged": {
+			"id": "BridgeMerged",
+			"description": "Notification that one bridge has merged into another.",
+			"properties": {
+				"bridge": {
+					"required": true,
+					"type": "Bridge"
+				},
+				"bridge_from": {
+					"required": true,
+					"type": "Bridge"
+				}
+			}
+		},
 		"ChannelCreated": {
 			"id": "ChannelCreated",
 			"description": "Notification that a channel has been created.",