add shortcut-keys for georeferenced images

[malenki]

It would enhance the workflow quite a bit if one could flip through the loaded images for- and backwards without having to drag the mouse over to the <- -> buttons all the time. If a shortcut for deleting images is to be invented too, I'd like to see a dialog of the [are you sure?]-kind.

Additionally, the wastebasket at the GUI should be moved outwards since clicking forward/backward with the mouse can cause unwanted deletion. But maybe the before mentioned dialog would already settle this.

[bastiK]

See #3722. Is this what you are asking for?

[malenki]

Oh, indeed. I didn't think I'd have to go back as far as that.

Any suggestions why PageUp/PageDown don't switch to previous next image here?
The only conflict shown is
Silent shortcut conflict: 'tools:jumpto' moved by 'tools:uploadtraces' to 'Strg+Umschalt+G'.

[bastiK]

Yes: Your version is outdated!

(It will be in tomorrow's latest.)

[bastiK]

I added a are you sure dialog for delete image file from disk. For the remove photo from layer function this isn't really necessary: The worst case scenario would be that one has to load the images again into JOSM.
(See r2627)