learn about uploadPortletRequest and YUI io-form-iframe in order to upload file
add upload attachment with workplanNode function.
Add proper permission to uploaded file in order to allow site member to view it.
add multiple file upload function. Change node -> attachment to one to many mapping.
add upload multiple files functionality.
complete the submit dialog, it will inditcate the submit progress now.
Complete file upload functionality, error message will also be shown on the page if upload failed.
add table header sortable configuration function. Now we can set sortable in table column enum.