Fixed issue with torrent file preallocation. CC @gubatron.
cleanup the other .torrent files not downloaded on complete. don't wait for transfer to be removed to cleanup.
new UXAction codes for settings tracking.
Split 'common/' into commit '01c2c3a09aac88f7333b48e73ad2041a033af785'

git-subtree-dir: common
git-subtree-mainline: 60ca37936b2a93c0980c0b8f77ad08e3289d11c4
git-subtree-split: 01c2c3a09aac88f7333b48e73ad2041a033af785