this lets bc use readline-4.2, borrowed from redhat apparently. :)

--- bc-1.06/bc/scan.l.sux	Fri May 11 14:27:20 2001
+++ bc-1.06/bc/scan.l	Fri May 11 14:27:32 2001
@@ -143,7 +143,6 @@
 
 /* Definitions for readline access. */
 extern FILE *rl_instream;
-_PROTOTYPE(char *readline, (char *));
 
 /* rl_input puts upto MAX characters into BUF with the number put in
    BUF placed in *RESULT.  If the yy input file is the same as