Inclusion of libsodium in pysodium #45

Hi,

Would you consider accepting a PR that makes pysodium an "autonomous" Python package (that would not depend on the presence of libsodium.so/libsodium.dll on the target system) ?

The idea would be to provide a wheel for all platforms and the binary dependency would no longer be required on Windows and OSX. On linux, installing the package would still require an available libsodium on the system (binary wheels are not supported for Linux afaik).

Users would only have to do:

pip install pysodium

To get a fully working pysodium. Checks for the library failure on import would also no longer be a concern for user-code.

Before I put on all the work for that, is this something you'd consider for inclusion ?

Thanks for the amazing work so far !