New: Show episode file file deletions in history and episode activity

This will show deletions (for upgrades, deleted from disk or deleted by the user), in history and activity for the episode. The main idea was to show upgrades, so we know for certain why a file was deleted (because it can be a bit of a guessing game w/o logs) and people lie (get things mixed up).
Only the series part really works, the lazy loading of episodes doesn't work, hence my hack below.