ShellApp: Change activation API

Since almost all of the callers of shell_app_activate were using the
default workspace (by passing -1), remove that parameter.

Add a new shell_app_activate_full() API which takes a workspace as
well as a timestamp; previously we might have been ignoring event
timestamps from elsewhere.

https://bugzilla.gnome.org/show_bug.cgi?id=648149

js/ui/docDisplay.js

@@ -30,11 +30,11 @@ DocSearchProvider.prototype = {
     },
 
     activateResult: function(id, params) {
-        params = Params.parse(params, { workspace: null,
-                                        timestamp: null });
+        params = Params.parse(params, { workspace: -1,
+                                        timestamp: 0 });
 
         let docInfo = this._docManager.lookupByUri(id);
-        docInfo.launch(params.workspace ? params.workspace.index() : -1);
+        docInfo.launch(params.workspace);
     },
 
     getInitialResultSet: function(terms) {