#415: Added feature for design time column header dragging and resizing. (Thx to fr0st.brutal)

git-svn-id: http://virtual-treeview.googlecode.com/svn/trunk@597 38df5cc4-5811-11de-992f-fdd7e25b9163
Minor fix for patch for issue #415: Wrong cursor was changed.

git-svn-id: http://virtual-treeview.googlecode.com/svn/trunk@598 38df5cc4-5811-11de-992f-fdd7e25b9163
Added support for XE6.

git-svn-id: http://virtual-treeview.googlecode.com/svn/trunk@599 38df5cc4-5811-11de-992f-fdd7e25b9163
Fixed issue #417: Updated a link

git-svn-id: http://virtual-treeview.googlecode.com/svn/trunk@600 38df5cc4-5811-11de-992f-fdd7e25b9163