Bug 239518 [Contributions] Fix up TextActionHandler's handling of Delete to use Text.insert
bundles/org.eclipse.ui.ide/extensions/org/eclipse/ui/actions/TextActionHandler.java
*
     * @param action the <code>IAction</code> to run for the
     *    Delete action, or <code>null</code> if not interested.
     */
    public void setDeleteAction(IAction action) {
        if (deleteAction == action) {
			return;
		}
        if (deleteAction != null) {
			deleteAction.removePropertyChangeListener(deleteActionListener);
		}
        deleteAction = action;
        if (deleteAction != null) {
			deleteAction.addPropertyChangeListener(deleteActionListener);
		}
        textDeleteAction.updateEnabledState();
    }
    /**
     * Update the enable state of the Cut, Copy,
     * Paste, Delete, and Select All action handlers
     */
    private void updateActionsEnableState() {
        textCutAction.updateEnabledState();
        textCopyAction.updateEnabledState();
        textPasteAction.updateEnabledState();
        textSelectAllAction.updateEnabledState();
        textDeleteAction.updateEnabledState();
    }
}