Bls signatures

[Raycoms]

Closes #4

This is an implementation to include the BLS threshold scheme of https://github.com/Chia-Network/bls-signatures

This includes:

• The binary, src and header files of BLS for easy usage. (Optionally those could be excluded from and the manual install requirements added to the readme file)
• Config files that include the necessary BLS keys
• A key generator
• The necessary PublicKey, PrivateKey, Signature and certificate implementations.

Additionally I had to add a way to load the master public key from file and set it in the replica config accordingly.

[Determinant]

Thanks for the PR!
While I've been busy recently, could you try to use git submodule to refer to the external BLS library? Copying all the files right into the repo is a huge change... (I saw 79 files are changed..omg)

[Raycoms]

Okay, will do as soon as I get to it.