Removing calls to deprecated functionality in favor of the new versions. Old version worked fine but shouldn't be used.
Follows-up:
* r75275: Introduced the updateTooltipAccessKeys function in the new library but didn't call it on document ready and left the deprecated one in the onloadhook-run in wikibits.js untouched
* r75287: Introduced jquery.checkboxShiftClick and called on-load but left the load call for the legacy version untouched. Depending on the load order at any given time it may not have been used.
Also reordering the if-else case in mw.util.updateTooltipAccessKeys to allow a call without arguments ("undefined instanceof Foo" throws exception)