This service will assemble metrics pertaining to delivery and encoding of jobs through Vector system.  Calculations will be based on datetime ranges specified either explicitly or relative to server system time.
GET metrics?dms_ids=<id>(,<id>)*&[start=<datetime>|start_back=<secs_back>]&[end=<datetime>|end_back=<secs_back>]&aggr=<aggr>(,<aggr>)
aggr: [cnt|min|max]
datetime: ISO 8601, example: "2012-04-21T18:25:43-0500"
secs_back: integer
{
	"data": {
		"stores": [
			{
				"dms_id": "...",
				"statuses": [
					{
						"code": "...",
						"label": "...",
						"priorities": [
							{
								"code": "enc",
								"label": "encoding",
								"metrics": [
									{
										"code": "...",
										"val": 123
									}
								]
							}
						]
					}
				]
			}
		]
	},
	"error": "..."
}