interactive shell detection in shrc

Our skel files use


case "$-" in *i*)
	# interactive mode settings go here
	;;
esac


which, IMO, is horrible for readability/usability as it suggests that
you add your changes to your shrc nested inside a case.

I'd like to switch this to the "early return" style, something like


# the rest of the file is for interactive shells only
case "$-" in *i*) ;; *) return ;; esac


Any objections?

-uwe