win32 graphisc control: passthrough MouseEnter and MouseLeave events (useful for nothing)

Bizware/BizHawk.Bizware.BizwareGL/GraphicsControl.cs

@@ -30,6 +30,8 @@ namespace BizHawk.Bizware.BizwareGL
 			//(dont use HTTRANSPARENT, it isnt portable, I would assume)
 			Managed.MouseDoubleClick += (object sender, MouseEventArgs e) => OnMouseDoubleClick(e);
 			Managed.MouseClick += (object sender, MouseEventArgs e) => OnMouseClick(e);
+			Managed.MouseEnter += (object sender, EventArgs e) => OnMouseEnter(e);
+			Managed.MouseLeave += (object sender, EventArgs e) => OnMouseLeave(e);
 
 			//the GraphicsControl is occupying all of our area. So we pretty much never get paint events ourselves.
 			//So lets capture its paint event and use it for ourselves (it doesnt know how to do anything, anyway)