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/context.rs

@@ -26,20 +26,6 @@ impl Context {
         }
     }
 
-    /// Load keystore and return Context
-    pub fn load_keystore<S: Into<String>>(mut self, name: S, password: S) -> Context {
-        let filename = &name.into();
-        match Keystore::from_file(filename, &password.into()) {
-            None => {
-                warn!("Error loading keystore '{}'!", filename);
-            },
-            Some(keystore) => {
-                self.keystore = Some(keystore);
-            },
-        }
-        self
-    }
-
     pub fn get_keystore(&self) -> Option<Keystore> {
         self.keystore.clone()
     }