Replaced JS-based centering with CSS [TODO: Make auto-centering a user option again!]
added options for autoCenter and blurBackground, added classes to all elements for styling
added unprefixed filter
check for existance of mask parent node before removing child
exclude qbContent and children from hidePopup click handler
fixed adding custom classes to qbContent
removed prescriptive styling from qbContent
updated minified js
Updated defaults, docs and demo
removed IDs added classes, also added multi popup demo back in