add blacklisted_regex to shhgit

As far as I know shhgit supports:

blacklisted_strings, blacklisted_extensions, blacklisted_paths and blacklisted_entropy_extensions.

Would it be possible to add blacklisted_regex so we can properly discard things we don't want? I can do it with grep on the output, but there are side cases, like when there is more than 1 match inside the same file, that one might match the regex (being a false positive) and will also discard the valid finding.