Bug 49117 [Plan Item] Workbench needs hooks for new welcome support
M6 We need to provide an extension point and some interfaces to allow for a primary feature to declare a welcome page. This extension point will be tied the new IProduct being defined by the Core team and needs to have 3 states 1) Fill whole screen 2) Collapsed on the right when the user selects something and starts working 3) Disables when it is no longer of any use
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/internal/ide/IDEWorkbenchAdvisor.java
if (workbenchAdvisor != null) {
			throw new IllegalStateException();
		}
		workbenchAdvisor = this;
	}
	/**
	 * Returns the single instance for this advisor. Can
	 * be <code>null</code> if not created yet.
	 */
	 static final IDEWorkbenchAdvisor getAdvisor() {
		return workbenchAdvisor;
	}
	
	/**
	 * Returns the workbench configurer for the advisor. Can
	 * be <code>null</code> if advisor not initialized yet.
	 */
	 IWorkbenchConfigurer getWorkbenchConfigurer() {
		return configurer;
	}
	
	/* (non-Javadoc)
	 * @see org.eclipse.ui.application.WorkbenchAdvisor#initialize
	 */
	public void initialize(IWorkbenchConfigurer configurer) {
		
		this.configurer = configurer;	
		
		
		configurer.setSaveAndRestore(true);