#4 Convert Threading

[A Schenck]

Replace Threadweaver with QThreadPool. Right now we don't use Thread Dependencies which is a major feature of ThreadWeaver compared to QThreadPool. Before replacing, lets examine if we could/should use Thread Dependencies to improve the user experience. I've envisioned being able to control multiple queues, one that's currently running updates, and then a second to install new packages once the update queue is finished.