altTab: Skip unminimize effect when cycling to a window

Similar to windows on another workspace, selecting a minimized window
doesn't look quite right - the selected window disappears, then animates
back in. Fix this by adding support for skipping the next effect to the
wm and use it to bypass the unminimize animation.

https://bugzilla.gnome.org/show_bug.cgi?id=771536

js/ui/altTab.js

@@ -448,6 +448,11 @@ const CyclerPopup = new Lang.Class({
         let ws = window.get_workspace();
         let activeWs = global.screen.get_active_workspace();
 
+        if (window.minimized) {
+            Main.wm.skipNextEffect(window.get_compositor_private());
+            window.unminimize();
+        }
+
         if (activeWs == ws) {
             Main.activateWindow(window);
         } else {