allow to scroll the virtual desktop further than the desktop geometry.

src/WindowMaker.h

@@ -407,6 +407,7 @@ typedef struct WPreferences {
 
 #ifdef VIRTUAL_DESKTOP
     unsigned int vedge_thickness;
+    unsigned int vedge_bordersize;
     unsigned int vedge_hscrollspeed;
     unsigned int vedge_vscrollspeed;
     unsigned int vedge_maxheight;

src/defaults.c

@@ -442,7 +442,7 @@ WDefaultEntry optionList[] = {
         &wPreferences.vedge_thickness, getInt,        NULL
     },
     {"VirtualEdgeExtendSpace", "0",   NULL,
-        &wPreferences.vedge_border, getInt,        NULL
+        &wPreferences.vedge_bordersize, getInt,        NULL
     },
     {"VirtualEdgeHorizonScrollSpeed", "1",  NULL,
         &wPreferences.vedge_hscrollspeed, getInt,     NULL