Usenet speed improvements

Let me know if It's better to spread these into different feature suggestions

- Easy integration of Torbox add-on / search with their own usenet indexers
- Improving speeds to achieve "close to instant" file streaming
a) Use Ramdisk for downloads and unpacking
b) Make sure CPU is not the bottleneck for unpacking speeds
c) Tune the connection to the providers to get better speeds (changing ports, enabling/disabling ssl, tune number of connections, change download manager to NZBGet and test since it doesn't use python, etc.)
d) Improve peering with the usenet server (identify where they are located, maybe contacting the provider support directly to set up a server close to them)