Switched to indent using tabs.
Hugely shrunk the UI.

- Web view is now hidden since login is not required.
- Checkboxes instead of popup button for HD/SD.
- Spinning progress indicator on launch while session info is retrieved.
- Display number of files completed.
Change Download button to Quit when downloading.
Add temporary ".download" suffix to file name.

This way, the user can see in Finder which files did not complete.