Qt has a bug QTBUG-72558, which leads to incorrect progress bar
position, when drawing it in delegate.
Also, since OS X 10.10 Yosemite macOS default style was changed,
and progress bars became very tiny and without text (percentage).
These two cases make qBittorrent look pretty awful, but drawing
progress bar in Fusion style solves both issues.
Change project directory structure according to application structure.
Change 'nox' configuration option to something more meaningful 'nogui'.
Rename 'Icons' folder to 'icons' (similar to other folders).
Partially add 'nowebui' option support.
Remove QConf project file.
