Set the workspace when launching apps

main.js: Add create_app_launch_context() with code from appDisplay;
  additionally set the workspace on the launch context to the current
  workspace so that the application launches on the right workspace
  even if the user switches before the app starts.

appDisplay.js docDisplay.js: Use Main.create_app_launch_context()

http://bugzilla.gnome.org/show_bug.cgi?id=580658 (Reported by Igor Vatavuk)

js/ui/docDisplay.js

@@ -8,6 +8,7 @@ const Shell = imports.gi.Shell;
 const Signals = imports.signals;
 
 const GenericDisplay = imports.ui.genericDisplay;
+const Main = imports.ui.main;
 
 const ITEM_DISPLAY_ICON_MARGIN = 2;
 
@@ -78,7 +79,12 @@ DocDisplayItem.prototype = {
             appExec = appExec.replace(/%/g, "%%");
 
             let appInfo = Gio.app_info_create_from_commandline(appExec, null, 0, null);
-            appInfo.launch([], null, null);
+
+            // The app launch context doesn't work as well as we might like because
+            // it doesn't get the right StartupNotify key from the application's
+            // desktop file. So, we don't get startup notification, the application
+            // doesn't stick to the current workspace, and so forth.
+            appInfo.launch([], Main.create_app_launch_context());
         } else {
             log("Failed to get application info for " + this._docInfo.get_uri());
         }