Fingerprint functionality

[Racopokemon]

Adressing #4, this is a simple fingerprinting functionality including a test case.
This commit also fixes a potential issues with file-splitting when adding further data to an already compressed benchmark.

[d-krupke]

Nice job!

[d-krupke]

You could have used sorted() instead of .sort to save one line. But this is just a minor style thing.

[Racopokemon]

I was not aware that sorted() was an option, it actually annoyed me when I realized that the .sort() would cost me an additional line. Thanks for mentioning it :D