Changed MDICreateChild to support CW_USEDEFAULT for 16-bit MDI
windows.

diff --git a/windows/mdi.c b/windows/mdi.c
index 9ce4d2e..92a4449 100644
--- a/windows/mdi.c
+++ b/windows/mdi.c
@@ -484,10 +484,10 @@
     /* calculate placement */
     MDI_CalcDefaultChildPos(parent, ci->nTotalCreated++, pos, 0);
 
-    if (cs->cx == CW_USEDEFAULT || !cs->cx) cs->cx = pos[1].x;
-    if (cs->cy == CW_USEDEFAULT || !cs->cy) cs->cy = pos[1].y;
+    if (cs->cx == CW_USEDEFAULT || cs->cx == CW_USEDEFAULT16 || !cs->cx) cs->cx = pos[1].x;
+    if (cs->cy == CW_USEDEFAULT || cs->cy == CW_USEDEFAULT16 || !cs->cy) cs->cy = pos[1].y;
 
-    if( cs->x == CW_USEDEFAULT )
+    if (cs->x == CW_USEDEFAULT || cs->x == CW_USEDEFAULT16)
     {
  	cs->x = pos[0].x;
 	cs->y = pos[0].y;