Hide scrollbar when not needed

[scottmc]

Not sure if this is doable or not, but at least in replicant mode it would look better to hide the scrollbar(s) rather than gray them out when they aren't needed.

[humdingerb]

I'd say get rid of the scrollbars, full-stop. These notes are supposed to be short.
It'd be best if the window auto-resized vertically whenever a new line of text is created/removed. If the user resizes the window vertically, the window height should be adjusted when the resize corner was released.