config(8) should check if a scheduler is selected

[Terry Lambert]

Mike Barcroft wrote:
> Since all `options' are optional, maybe `sched' should be its own
> directive with two possible values: `4BSD' or `ULE'.

No.

1)	It's fixable without this, by allowing them to coexist and
	be selected at boot time.

2)	Config needs to die, not grow larger.

-- Terry