segmentio/modal — pull request #6 by lmartins (2014-06-23 21:16:41+00:00)
Title: Center modal in the screen for fade-and-scale effect

This one im not completely sure if you want to integrate, but I do think it makes sense.
The changes allow the modal to be exactly at the center of the screen, while before with was dislocated, which was quite apparent for longer modals, with an height close to the screen height.