Touch DnD only partially works

[yassam]

The documentation says that DnD should work with Touch:
https://github.com/SitePen/dgrid/blob/master/doc/components/extensions/DnD.md

It mentions the test file DnD_touch.html as an example.

I tried this file in both Safari on an iPhone and the Samsung browser on Android, and in both cases it was a hit and miss affair. In both cases, it kept dragging and dropping the wrong row most of the time.