remove lastRender calcul
optimize member center. stop fetching every time.
goto member center onClickLeftBtn for 4 pages, where goBack loop may
occur
fetch profile, contacts and favorites on login.
use custom confirm dialog insead of device/browser's native dialog.
use model.save instead of backbone.sync. onerror arguments are
different.
reset member center's render flag on logout
fix displayError, show 'Error' on null responseText. fix error func on
product redeem page.