crypto: Move encoding logic to JS, default=buffer

crypto: Hash and Hmac default to buffers

crypto: Move Cipher encoding logic to JS

crypto: Move Cipheriv encoding logic to JS

crypto: Move Decipher encoding logic to JS

crypto: Move Decipheriv into JS, default to buffers

crypto: Move Sign class to JS

crypto: Better encoding handling in Hash.update

crypto: Move Verify class to JS

crypto: Move DiffieHellman to JS, default to buffers

crypto: Move DiffieHellmanGroup to JS, default to buffers

Also, create a test for this feature