[patch] Listview drag-and-drop fix

[Paul Rupe]

Xnews was treating all mouseclicks as drag-and-drop operations in the 
newsgroup listview.  The problem was that LISTVIEW_TrackMouse was losing 
the WM_LBUTTONUP message.  This patch adds the missing call to 
DispatchMessage.

License:  X11, LGPL
Changelog:  <prupe(a)myrealbox.com>
  Dispatch the last message when exiting LISTVIEW_TrackMouse


-- 
Paul Rupe   <prupe(a)myrealbox.com>                "She smiled, in the end."