Take data from EXIF field SubSecTimeOriginal into account

[bluepup]

The EXIF specification allows to tag an image with a time of finer resolution than just seconds.
With GPS receivers allowing position updates of several positions per second and compasses or IMUs even higher update rates it makes sense to use SubSecTimeOriginal to match with the gps data.

[dfandrich]

That's on my personal TODO list. Once I merge the direction feature, I'll probably look at that.

[reubot]

Once I merge the direction feature

Any updates on this?