add "rotate image" command to the contextmenu...

[klumy]

... so you can also rotate the image in fullscreen mode

[Koogle]

they still exist as hotkeys [shift]+[L]/[R] ...but sometimes I just use the mouse and not that interesting doing hotkeys.. so I in favour of adding it to the context menu within Xnview. As there are times when I just open an image just to rotate/save