ShellApp+ShellGlobal: unify app launch context code

Extend shell_global_create_app_launch_context() with the required
parameters and use that for shell_app_launch() too.

https://bugzilla.gnome.org/show_bug.cgi?id=669603

js/ui/remoteSearch.js

@@ -283,7 +283,7 @@ const RemoteSearchProvider = new Lang.Class({
         // the provider is not compatible with the new version of the interface, launch
         // the app itself but warn so we can catch the error in logs
         log('Search provider ' + this.appInfo.get_id() + ' does not implement LaunchSearch');
-        this.appInfo.launch([], global.create_app_launch_context());
+        this.appInfo.launch([], global.create_app_launch_context(0, -1));
     }
 });