Bug 71800 [IDE] Clean action should be background operation
build R3.0 When the user selects "Clean..." from the Project menu, it pops up a modal dialog which shows progress. After the "clean" part is done, then the build is done in the background. The "clean" action should also be done in the background. The inconvenience of having it in the foreground is magnified when you have many projects with lots of source files (so it does real work and takes many seconds...up to a minute)
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/internal/ide/dialogs/CleanDialog.java
private Button allButton, selectedButton, buildNowButton;
    private Text projectName;
    private Object[] selection;
    private IWorkbenchWindow window;
    /**
     * Gets the text of the clean dialog, depending on whether the
     * workspace is currently in autobuild mode.
     * @return String the question the user will be asked.
     */
    private static String getQuestion() {
        boolean autoBuilding = ResourcesPlugin.getWorkspace().isAutoBuilding();
        if (autoBuilding)
            return IDEWorkbenchMessages.getString("CleanDialog.buildCleanAuto"); 
        return IDEWorkbenchMessages.getString("CleanDialog.buildCleanManual"); 
    }
    /**
     * Creates a new clean dialog.
     * 
     * @param window the window to create it in
     * @param selection the currently selected projects (may be empty)
     */
    public CleanDialog(IWorkbenchWindow window, IProject[] selection) {
        super(
                window.getShell(),
                IDEWorkbenchMessages.getString("CleanDialog.title"), null, getQuestion(), QUESTION, new String[] {