Update libsodium and dnscrypt to latest versions

Hi Simon,

Quite simply, Frank has updated the libsodium library from 0.6.1 to 0.7.and then to 1.0.
I tested it and it works. I also tested it using the dnscrypt-autoinstall script.

The same goes for the dnscrypt proxy version from 1.4.0 to 1.4.1

Best regards,
Maciej