Rotate background image

[morgular]

I searched and found https://www.sweethome3d.com/support/for ... read,11798 this thread.

It would be nice to have an additional step when importing a picture, probably as step 1 would be the best.
"Rotate image"
- a horizontal (and / or vertical one?) line to snap to (fixed?)
- a line similar to the "Scale" one, for moving around while zooming in and out
- "preview" button or "test" or something like that
- "OK" button to get to the scaling screen

Yeah, ic could be done before in an external program, but its sometimes quite cumbersone as ease of use is not the goal because the tools are quite mighty.

I think this would be quite usefull without trying to make the import assistant an image editor.