Implement the http variant of the bank server.

During that process, many shortcomings with the socket server and the
bank lib were fixed.

I am aware a massive commit like this is not ideal.

socket-server/src/main.rs

@@ -1,10 +1,10 @@
 #[macro_use]
 extern crate log;
 
+mod commands;
 mod protocol;
 mod server;
 mod threadpool;
-mod commands;
 
 fn main() {
     pretty_env_logger::init();