data-title and data-footer attributes overrides initial config

[zephir89]

Hi!
I noticed that data-title and data-footer attributes overrides initial config. So, if I create an instance of lightbox like this

$("#link").ekkoLightbox({
    title: "Title",
    footer: "Footer",
    alwaysShowClose: true
});

with:

<a href="url" id="#link" >

modal header and footer will be empty because data-title and data-footer are missing.
I think the issue is in _updateTitleAndFooter function unless I misunderstand how it works.
Thank you for your great work!

Daniele