Support for Redis Session Management

Config file example :
	"Change":{
		"Session":{
			"SaveHandler":{
				"type":"redis",
				"options":{
					"server":{
						"host":"127.0.0.1",
						"port":6379
					},
					"database":0,
					"ttl":900,
					"namespace”:”my_unique_ns”
				}
			}
		}
Generalize for an arbitrary type
Merge pull request #1001 from franckstauffer/redis

Support for Redis Session Management