display the time for geotagged fotos

[dieterdreist]

sometimes it would be really useful to have the time displayed (incl. seconds) in the gps-photo-windows (in the upper part where the image name, altitude and heading is shown, there is 3 lines of space and usually most of it is empty). This way you could see in case of bad GPS-reception how far (in terms of time) 2 images are afar (and if it's a few seconds and you were walking you'd know that the pictures must be very close, also if the track was drifting quickly due to poor reception).

[Don-vip]

In 5432/josm:

fix #7822 - display the EXIF/GPS time for geotagged images, when known