applied configureawait to eleminate the deadlock problem.

I had to have the following query on the `IAsyncDocumentSession` as ASP.NET MVC child actions don't support async:

	[ChildActionOnly]
	public ActionResult List()
	{
		IEnumerable<Tags_Count.ReduceResult> tags = _documentSession
			.Query<Tags_Count.ReduceResult, Tags_Count>()
			.ToListAsync()
			.Result;

		return View(tags.Select(tag => new TagModel
		{
			Name = tag.Name,
			Slug = tag.Slug,
			Count = tag.Count,
			LastSeenAt = tag.LastSeenAt
		}));
	}
	
However, this call will cause a deadlock because of the reasons explained in the following articles and questions:

 - [The Perfect Recipe to Shoot Yourself in The Foot - Ending up with a Deadlock Using the C# 5.0 Asynchronous Language Features][1]
 - [Asynchronous .NET Client Libraries for Your HTTP API and Awareness of async/await's Bad Effects][2]
 - [Best practice to call ConfigureAwait for all server-side code][3]
 
Hope this helps.

  [1]: http://www.tugberkugurlu.com/archive/the-perfect-recipe-to-shoot-yourself-in-the-foot-ending-up-with-a-deadlock-using-the-c-sharp-5-0-asynchronous-language-features
  [2]: http://www.tugberkugurlu.com/archive/asynchronousnet-client-libraries-for-your-http-api-and-awareness-of-async-await-s-bad-effects
  [3]: http://stackoverflow.com/questions/13489065/best-practice-to-call-configureawait-for-all-server-side-code
  
Not completely sure if this pull-request completely fixes this problem (as nearly every await needs to be made against `ConfigureAwait(false)` in a library which doesn't care about the sync. context) but I just wanted to raise the problem here with this pull request.