Added in 1.9.2
Trigger when a user releases a key in a window.
<level> - The level for the event to trigger.
<*#?=!@> - The Matchtarget to listen to.
<key,...,keyN> - The $keyval to listen to.
<commands> - The commands to be performed when the event listener's criteria is met.
on *:KEYDOWN:*:*:echo -ag Released key $keyval in $active