* sbr/ambigsw.c: Send print_sw output to stderr. This avoids

	* sbr/ambigsw.c: Send print_sw output to stderr.  This avoids
	strange problems with scan `pick -bogus`, not to mention being
	nicer anyway.

	* sbr/getans.c, sbr/print_help.c, uip/msh.c: Send print_sw output
	to stdout.

	* h/prototypes.h, sbr/print_sw.c (print_sw): Add FILE * argument
	and send output there rather than to stdout.

	* test/tests/pick/test-stderr: Add test that error messages don't
	end up going to stdout.