Improve async usage

[GeertvanHorrik]

For example, this code:

    using System.Threading.Tasks;
    using Windows.Storage;

    public class ImageCache
    {
        public static async Task<StorageFile> Load(string url)
        {
            return await Load(url, null);
        }

        public static async Task<StorageFile> Load(string url, Crop crop)
        {
            return await Loader.CacheManager(url, crop);
        }

Can be rewritten as:

    public class ImageCache
    {
        public static Task<StorageFile> LoadAsync(string url)
        {
            return LoadAsync(url, null);
        }

        public static Task<StorageFile> LoadAsync(string url, Crop crop)
        {
            return Loader.CacheManager(url, crop);
        }

1. (I think) it's best to postfix async methods with 'Async'
2. Don't use async Task if you are only awaiting a single task, just return the task (saves a task object that also needs garbage collecting, etc)