File Downloader

Need a solution in .net and c# to be able to download files reliably basically if there is an intermittent connection we should be able to resume the download where ever possible instead of starting from the beginning. Some CDNs support downloading partial content and if the URL doesn't support partial downloads you need to download the whole file again.

Needs
1. Unit Tests
2. File integrity
3. Cancellation Process (to stop download)
4. Bandwidth Limiter (amount of bandwidth that can be used for download ex. netlimiter)
5. Progress Indicator (optional)