RavenDB-1417

Endpoint output:

{
	NumberOfCurrentlyWorkingIndexes: 2,
	Indexes: [
	{
		IndexName: "Raven/DocumentsByEntityName",
		IsMapReduce: false,
		CurrentOperations: [
			{
			Operation: "Current",
			NumberOfProcessingItems: 16384
			}
		],
		LastMapRate: "0.1670 ms/doc",
		Priority: "None",
		OverallIndexingRate: [
			{
			Operation: "Index",
			Rate: "0.2384 ms/doc"
			}
		]
	},
	{
		IndexName: "SampleDataReduce/Index",
		IsMapReduce: true,
		CurrentOperations: [
		{
			Operation: "Current Map",
			NumberOfProcessingItems: 16383
		}
		],
		LastMapRate: "0.1554 ms/doc",
		Priority: "None",
		OverallIndexingRate: [
			{
				Operation: "Map",
				Rate: "0.2170 ms/doc"
			},
			{
				Operation: "Reduce Level 2",
				Rate: "0.0185 ms/doc"
			}
		]
	}
	]
}