NSTableView/NSTableHeaderView changes in CVS

[Pierre-Yves Rivaille]

Hi,

I've implemented column reordering in NSTableView and made the column
resizing more coherent. During resizing and reordering, the table view
scrolls automatically if needed !

However there are a few remainings small graphics bug during column
reordering that I will work out in the few next days.

If you find any bugs or misbehaviours using the table view, I'll be
pleased to hear about them and to work them out.

I will also try to implement the missing features of NSTableView
(autoresizing column to fit, ...) during this week.

Pierre-Yves Rivaille