Change feed support in Azure Cosmos DB

Now available in preview, the [change feed support](https://github.com/Azure/azure-documentdb-changefeedprocessor-dotnet) in Azure Cosmos DB allows you to build efficient and scalable solutions. Change feed is enabled by default for all accounts. It outputs the sorted list of documents that were changed in the order in which they were modified. The changes are persisted, can be processed asynchronously and incrementally, and the output can be distributed across one or more consumers for parallel processing. [Learn more.](https://github.com/Azure/azure-documentdb-changefeedprocessor-dotnet) * Features