Show horizontal drag-and-drop line during row-reordering

[simonwep]

Note

As originally reported by @zenminimalist

Moving of rows is a bit cumbersome as a new user would have to read the tool tip every time to make sure where the row is getting moved to. Instead, it would be better (and is more commonplace) to have a horizontal line during the moving process to indicate where the row is being moved to.