Fix array.sort.

array.sort was broken since 2001 when the implementation was changed
from merge sort to SAM sort.

library/array.m:
	Fix the confusion as to which output argument of samsort_up is
	sorted.

	Add optional runtime checks of the pre- and post-conditions
	of samsort_up and samsort_down when built with a trace flag.

	Add array.sort_fix_2014.

tests/hard_coded/Mmakefile:
tests/hard_coded/array_sort.exp:
tests/hard_coded/array_sort.m:
	Add test program.

NEWS:
	Announce the fix.