Added second keypair for encryption of domain names.

Changed keys file format to include second pair of keys, it will be in TOML now.
Made many adjustments to block and transaction structures.
Changed block serialization to binary format for hashing/mining.
Removed old build dependencies.

src/crypto/mod.rs

@@ -1,3 +1,3 @@
-mod chacha;
+mod crypto_box;
 
-pub use chacha::Chacha;
+pub use crypto_box::CryptoBox;