Preprocessing

The rest of the preprocessor is emulated by

     last if ( /^SCAN_CELLS/);

Now we can eliminate preprocess
- Also INFILE2, OUTFILE2, $input2, $output2
Net gain: 10 lines gone
While we're in the neighborhood, let's fix these error messages:

       7        open (INFILE,"$input1")||die "cannot open $input1";
       8        open(OUTFILE,">$output")||die "canoot\n";
       9        open(OUTFILE2,">$output2")||die "canoot\n";

Better:

       open (INFILE, "$input")   || die "cannot open $input: $!";
       open (OUTFILE,">$output") || die "cannot open $output: $!";