For aria2c I've simplified the operation by offloading most of the work for creating a cookie header by just re-doing what Python-requests does. This results in the exact same cookies Python-requests would have used in a requests.get() call or such. It supports multiple of the same-name cookies under different domains/paths based on the URI of the mock request.
These only happen if we intentionally cancel the process, or failed. However, this is something that is generally obvious given the args, and when cancelling a wall of these logs would appear.
I've removed asyncio usage as it's generally unnecessary. If you want to run aria2c under a thread, run it under a thread. In the case for devine, this would take another thread, and would be another thread layer deep. Pointless. Would affect speed.
With this change I've been able to improve the aria2c progress capture code quite a bit.
Turns out, even if you manually set the Range header AND the server has full support, it does not work. It will act like it works, but it seems internally aria2c gets confused on what bytes it requested, what it returned, and it will either just download the full file, or the range requested (but still complain, and freeze!).
Yikes.
