add XTaskAsync method overloads about azure-sdk-for-net

[prabirshrestha]

I have created a new library which is a single .cs file.

You can install it from nuget. Install-Package WindowsAzure.Storage.Tasks.

https://nuget.org/packages/WindowsAzure.Storage.Tasks

You can find the entire code for it at https://github.com/prabirshrestha/azure-sdk-for-net-tasks/blob/master/src/AzureStorageClientTaskExtensions/StorageClientTaskExtensions.cs (Right now it contains common methods that I use frequently.)

For long run, I would like these to move into as core methods which are not extension methods so that it can be unit testable.

[jdom]

+1. A native implementation that also supports cancellation tokens is very much needed, otherwise using exponential backoff strategies for retrying make scenarios that need cancelling (like disposing an object) very difficult.

[joeg]

This functionality will be available in our next release (2.1) which is currently in testing.

joe

[jeffwilcox]

2.1 has shipped. Closing.