Added option for ability to move half-maximized between heads.

Added new option to Window Maker preferences to enable half-maximized
windows movement on all available heads. Option can be found in WPrefs
app on Expert section.

WPrefs.app/Expert.c

@@ -100,6 +100,9 @@ static const struct {
 	{ N_("Snapping a window to the top maximizes it to the full screen."),
 	  /* default: */ False, OPTION_WMAKER, "SnapToTopMaximizesFullscreen" },
 
+	{ N_("Allow move half-maximized windows betweem multiple screens."),
+	  /* default: */ False, OPTION_WMAKER, "MoveHalfMaximizedWindowsBetweenScreens" },
+
 	{ N_("Open dialogs in the same workspace as their owners."),
 	  /* default: */ False, OPTION_WMAKER, "OpenTransientOnOwnerWorkspace" }
 

src/WindowMaker.h

@@ -365,6 +365,7 @@ extern struct WPreferences {
 	int snap_corner_detect;            /* how far from corner to begin snap */
 	char snap_to_top_maximizes_fullscreen;
 	char drag_maximized_window;        /* behavior when a maximized window is dragged */
+	char move_half_max_between_heads;  /* move half maximized window between available heads */
 
 	char highlight_active_app;         /* show the focused app by highlighting its icon */
 	char auto_arrange_icons;           /* automagically arrange icons */

src/defaults.c

@@ -482,6 +482,8 @@ WDefaultEntry optionList[] = {
 	    &wPreferences.snap_to_top_maximizes_fullscreen, getBool, NULL, NULL, NULL},
 	{"DragMaximizedWindow", "Move", seDragMaximizedWindow,
 	    &wPreferences.drag_maximized_window, getEnum, NULL, NULL, NULL},
+	{"MoveHalfMaximizedWindowsBetweenScreens", "NO", NULL,
+	    &wPreferences.move_half_max_between_heads, getBool, NULL, NULL, NULL},
 	{"HighlightActiveApp", "YES", NULL,
 	    &wPreferences.highlight_active_app, getBool, NULL, NULL, NULL},
 	{"AutoArrangeIcons", "NO", NULL,