rubendv
Boxer for secret sharedkey
Boxer/unboxer can now work with a secret preshared key, instead of my privkey + his pubkey.
Done as other constructor.
Needed to move stuff to a base class so it's nicer, but it should be 0-overhead (base class doesn't have vtable).
@rubendv thanks for wording corrections, will apply them soon.
About the TODO, it's for an issue we found, we're not yet fixing it and our code still does same mistake for now - #14
There is one important thing wrong in this PR we made: it does not make too much sense for unboxer to have default value of nonce_constant (the random nonce). We should I guess document that, or just remove the defaulted value.
Okay, I'll wait for you to fix the default value and then it can be merged. Thanks for the PR!
