.slider() keyboard support: stop fires continuously, not onkeyup

[pd]

When using a slider with the keyboard, holding down the left/right
arrow keys to slide the pointer left/right, the stop state fires
continuously.

This seems illogical because the user clearly has not 'stopped' making
their choice if they are holding down a navigation key.

This is contradictory to how slider mouse support works where the stop
state is only fired when the slider marker is released.

If a function is required to fire continuously, the slide state caters
for this.

If a function is required to fire when the value changes, the change
state caters for this.

However if a function is *only* required to fire when the user has
stopped using the slider, the stop state is broken.

I have a test case for this issue here:

http://devel.webutils.vicnet.net.au/testsuite/slider/

using the most recent SVN code so that rev 806 and 808 bugs do not
interfere.

Can anyone have a look at this issue and see if what
I've identified I've described well? If so I might lodge a bug.

Thanks
pd