[XGrid] Column resizing is too limiting

[oliviertassinari]

I believe that extending the resizing session up to the mouse up event would improve the UX. I don't think that we should interrupt the resizing session when the mouse leaves the column header. This surface area is relatively small. It would be better for end-users not to have to concentrate on keeping the same vertical alignment with their pointing device. It also feels weird to have the mouse pressed but not doing anything (once escaping the zone).

KO

OK