Honor screen size options.

diff -Nur main.sofar/libvo/vo_directx.c main.dev/libvo/vo_directx.c
--- main.sofar/libvo/vo_directx.c	(revision 19342)
+++ main.dev/libvo/vo_directx.c	(working copy)
@@ -1072,6 +1072,8 @@
     mplayercursor = LoadCursor(NULL, IDC_ARROW);
     monitor_rect.right=GetSystemMetrics(SM_CXSCREEN);
     monitor_rect.bottom=GetSystemMetrics(SM_CYSCREEN);
+    if (vo_screenwidth) monitor_rect.right = monitor_rect.left + vo_screenwidth;
+    if (vo_screenheight) monitor_rect.bottom = monitor_rect.top + vo_screenheight;
 	
     windowcolor = vo_colorkey;
     colorbrush = CreateSolidBrush(windowcolor);
@@ -1270,7 +1272,9 @@
 config(uint32_t width, uint32_t height, uint32_t d_width, uint32_t d_height, uint32_t options, char *title, uint32_t format)
 {
     RECT rd;
+    if (!vo_screenwidth)
     vo_screenwidth = monitor_rect.right - monitor_rect.left;
+    if (!vo_screenheight)
     vo_screenheight = monitor_rect.bottom - monitor_rect.top;
     vo_fs = options & 0x01;
 	image_format =  format;