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
/**
	 * Restore auto builds if temporarily disabled.
	 * Assumes that workbench windows have already been restored.
	 * <p>
	 * Use a WorkspaceModifyOperation to trigger an immediate build.
	 * See bug 6091.
	 * </p>
	 */
	private void enableAutoBuild() {
		if (autoBuild) {
			IWorkbenchWindow windows[] = PlatformUI.getWorkbench().getWorkbenchWindows();
			Shell shell = windows[windows.length - 1].getShell();				
			try {
				WorkspaceModifyOperation op = new WorkspaceModifyOperation() {
					protected void execute(IProgressMonitor monitor) throws CoreException {
						monitor.setTaskName(IDEWorkbenchMessages.getString("Workbench.autoBuild"));	
						IWorkspace workspace = ResourcesPlugin.getWorkspace();
						IWorkspaceDescription description = workspace.getDescription();
						description.setAutoBuilding(true);
						workspace.setDescription(description);
					}
				};
				IWorkbenchWindow window = PlatformUI.getWorkbench().getActiveWorkbenchWindow();
				if (window != null)
					window.run(true, true, op);
				else
					new ProgressMonitorDialog(shell).run(true, true, op);
			} catch (InterruptedException e) {
			} catch (InvocationTargetException exception) {
				MessageDialog.openError(