======Synopsis:======
[[on]] [<modes>]unload [<serial#>] [-|^]<match> { <action> }

======Description:======
This hook is triggered whenever the [[unload]](5) command is issued to unload
a packaged script.

======Parameters:======
|$* |the parameters passed to the /[[package]] command|
(NOTE that passing more than one argument to /[[package]] may cause
future incompatibilities, and should be avoided at all costs)

======Examples:======
To inform the user that a script is exiting:
   on ^unload "superscript *" {
      xecho -b SuperScript exiting. To infinity, and lots farther!
   }