Vcf symlink

This is a pretty junky script for Operations and/or data-transfer to symlink a bunch of build's SNV and Indel files. It is unclear to me how to test this so the test case is just a use of the module.
Tom's point earlier is that strings and regular expressions are two different things.  So `exclude` cannot "be a string or a regular expression"; it's one or the other.  If it's a string then you should use `\Q\E` to escape regular expression characters.  For example,

```
my $input = '.';
my $string = 'bob the builder';
my $match = ($string =~ /$input/) ? 'does =~' : 'does not =~';
print qq('$string' $match /$input/\n);
$match = ($string =~ /\Q$input\E/) ? 'does =~' : 'does not =~';
print qq('$string' $match /\Q$input\E/\n);
```

```
'bob the builder' does =~ /./
'bob the builder' does not =~ /\./
```