toolbar in imageviewer

- Ctrl-S = Save current, Shift-Ctrl-S = Filedialog

- allow to split browser into subwindows (multiple browsers)
- mouse-usage better (e.g. left button = next image, middle button = previous
  image, all configurable)
- anim-gif support (QMovie perhaps)
- cropping images (via Imlib_clone_scaled_image & Imlib_crop_and_clone_image())
- thumbnail view, treeview
- menubar (same as popupmenu) (abschaltbar) (mac-mode!)

- configure-dialog: offer a directory to copy files to -> one click copies to it
- rename/delete into popupmenu of imagewindow

- if image not readable -> no nagscreen, jump to next image
- network transparency with kio

- small preview in browser window
- bookmarks?
- generate wallpaper (background desktop image)
- display more image information (resolution, color depth, image comments...)
- better slideshow (randomize, pause/continue, reverse, ...)
- what else?
