#10732: works when Trac 0.11.1 and later, do nothing when Trac 0.11
#10732: works well with jQuery 1.2.x on Trac 0.11.x. `first()` method is available in jQuery 1.4+.
#10732: fixed wrong orders after reordering with jQuery 1.2 and jQueryUI 1.6
#10732: prevents the event bubbling of select widgets in order to be able to select on Firefox with jQuery UI 1.6