Async SFTP Client

This project aims to create async SFTP client API's for libSSH. Currently sftp_write is the only way of uploading files over SFTP using libssh but sftp_write is a synchronous write. Providing an asynchronous api for upload will make the upload process much more faster. A high level API which will internally use the low level async API for uploads and downloads will also be created which will make uploads/downloads easier for the user and more efficient since the async API is used internally. The set of deliverables for this project will be : a low level async API for writing, a high level API for upload and download, tests for the created API's, benchmark code to analyse performance of the API's, documentation for the created API's.