+PH/17 Applied (a modified version of) Nico Erfurth's patch to make
+ spool_read_header() do less string testing, by means of a preliminary
+ switch on the second character of optional "-foo" lines. (This is
+ overdue, caused by the large number of possibilities that now exist.
+ Originally there were few.) While I was there, I also converted the
+ str(n)cmp tests so they don't re-test the leading "-" and the first
+ character, in the hope this might squeeze out yet more improvement.
+