Check the ethi is actually the one being dragged. Prevents crashes when

2000-02-12  Iain Holmes  <ih@csd.abdn.ac.uk>

	* e-table-header-item.c (ethi_drag_motion): Check the ethi is actually
	the one being dragged. Prevents crashes when trying to drag headeritems
	and there are multiple headeritems on the same canvas.
	(ethi_drag_end): Same.
	(ethi_drag_drop): Same.
	(ethi_drag_leave): Same.

svn path=/trunk/; revision=1745