SetWindowMonitor made functioning again. (#1036)

* We get the video mode from the target monitor and use that to set, therefore
keeping windowed-fullscreen
* Added a GLFW_AUTO_ICONIFY 0 hint so that glfw does not minimize the window
when changing focus from a windowed fullscreen window. This is more expected
behavior for windowed full screen, when a user alt-tabs or clicks on a window in
the other monitor, they expect their windowed-fullscreen window to remaining up.

src/core.c

@@ -933,8 +933,9 @@ void SetWindowMonitor(int monitor)
 
     if ((monitor >= 0) && (monitor < monitorCount))
     {
-        //glfwSetWindowMonitor(window, monitors[monitor], 0, 0, screenWidth, screenHeight, GLFW_DONT_CARE);
         TraceLog(LOG_INFO, "Selected fullscreen monitor: [%i] %s", monitor, glfwGetMonitorName(monitors[monitor]));
+        const GLFWvidmode* mode = glfwGetVideoMode(monitors[monitor]);
+        glfwSetWindowMonitor(window, monitors[monitor], 0, 0, mode->width, mode->height, mode->refreshRate);
     }
     else TraceLog(LOG_WARNING, "Selected monitor not found");
 #endif
@@ -2743,6 +2744,15 @@ static bool InitGraphicsDevice(int width, int height)
             }
         }
 
+#if defined(PLATFORM_DESKTOP)
+        // If we are windowed fullscreen, ensures that window does not minimize
+        // when focus is lost.
+        if (screenHeight == displayHeight && screenWidth == displayWidth)
+        {
+            glfwWindowHint(GLFW_AUTO_ICONIFY, 0);
+        }
+#endif
+
         TraceLog(LOG_WARNING, "Closest fullscreen videomode: %i x %i", displayWidth, displayHeight);
 
         // NOTE: ISSUE: Closest videomode could not match monitor aspect-ratio, for example,