Unable to set CSS cursor on sortable helper

Any CSS `cursor` property is ignored on the sortable helper, and the cursor on the screen is determined by the background content that the helper is currently being dragged over (this part of the bug is actually the weirdest to me). Example here: https://jsfiddle.net/pufcv77k/3/

The problem appears to have been introduced here: https://github.com/clauderic/react-sortable-hoc/pull/160. It looks like that change fixes scrolling-while-dragging only when the sortable items are in a container with `overflow: auto;`, but perhaps I'm missing another scenario?

Not sure what the fix is here, if anything. I'd prefer not to have to set `pointer-events: auto !important;` to allow a custom cursor (and quash the weird background cursor behavior), but I'm not sure which behavior is preferred as default.

Reproduce the behavior using the linked JSFiddle, then read pull request #160 to understand the scrolling change and its effect on the sortable helper. Compare cursor behavior while dragging over background content and inside an overflow:auto container. Done means the intended custom cursor behavior is restored without regressing scrolling while dragging.

Written by the indexing model from the issue text.