Emit signal from Application once Workspace is created

Allows interesting parties to delay initialization till Workspace is
ready.

main.cpp

@@ -372,6 +372,7 @@ void Application::createWorkspace()
 
     // create workspace.
     (void) new Workspace(isSessionRestored());
+    emit workspaceCreated();
 }
 
 void Application::createInput()

main.h

@@ -150,6 +150,7 @@ public:
 
 Q_SIGNALS:
     void x11ConnectionChanged();
+    void workspaceCreated();
 
 protected:
     Application(OperationMode mode, int &argc, char **argv);