Reverts the changes made by users to a default image style.
style: An image style array.
Boolean TRUE if the operation succeeded.
function image_default_style_revert($style) {
image_style_flush($style);
db_delete('image_effects')
->condition('isid', $style['isid'])
->execute();
db_delete('image_styles')
->condition('isid', $style['isid'])
->execute();
return TRUE;
}