Use $option.val() because $option.attr('value') no longer falls back to .prop() to get the value in JQuery 1.9
Workaround for http://bugs.jquery.com/ticket/14101 in JQuery 1.9 and 1.10
Simplify initial selection selector
Upgrade to jquery 1.9
Upgrade to jquery 1.10

It changes the behaviour when setting initial selection
with config to something that does not exist in <select>
so that $select.val() returns null.