Remove use of deprecated "hover" pseudo-event

The "hover" pseudo-event was deprecated in jQuery 1.8 and removed in
1.9. This is logged as "JQMIGRATE: 'hover' pseudo-event is deprecated,
use 'mouseenter mouseleave'". This fix switches to using the .hover()
method which appears to be the original intent as two functions have
been used which .hover() supports, whereas .on() only accepts one
handler. Now the class change works as expected.

Change-Id: Ib28801293b72f8f344455b5f308876d185abc8bd