Use latin1, --pure_barcode and no universal_newlines

[parmegv]

latin1 allows us to handle ciphertext (tested with ASCON cipher).

pure_barcode is required to get binary data

universal_newlines was assuming all \r were \n, but with encrypted data it is not the case.

[oostendo]

I guess this looks like you've customized it for a specific application -- that's great, and I'm glad it works for you. I guess to accept this I would ask that all of these changes could be parameter controlled in the decode() function similar to what you did for pure_barcode.