Add panel param to hide_panel command

I have written a plugin that uses output panels to display the result of an operation. I tried to implement an option so the output panel would hide after a specified timeout. Unfortunately the hide_panel command does not accept a panel parameter, so if the user's focus has changed to another panel (such as Goto Anything), that panel will be closed instead.

I would very much appreciate it if you would add an optional panel param to the hide_panel command. Thanks!