Add background bitmap images

[goatchurchprime]

You can put in a second survey (faded) in the background of the current survey.

How about allowing this to be a bitmap image as well?

Then this would allow ST to work off a historical survey and continue onwards, or from a aerial photo surrounding a cave entrance (when starting off), or be used to trace up old surveys (and replace tunnel and therion).

The bitmap should preferably be in geotiff format so that it comes with the correct scale and coordinate system. This way it would have the convenience of qgis and there would be no need to develop user interface features for georeferencing.

[richsmith]

Could be useful. On the backlog.