Move blowfish stuff into it's own module

This cleans up the big src folder we have, this doesn't have any API changes
though.

src/blowfish/mod.rs

@@ -3,7 +3,8 @@
 
 use std::io::{Cursor, Write};
 
-use crate::blowfish_constants::{BLOWFISH_P, BLOWFISH_S};
+mod constants;
+use constants::{BLOWFISH_P, BLOWFISH_S};
 
 const ROUNDS: usize = 16;
 const KEYBITS: u32 = 64u32 >> 3;

src/lib.rs

@@ -46,8 +46,6 @@ pub mod patch;
 /// Implementation of the Blowfish ECB block cipher used by the retail client. It's used to encrypt arguments in the launcher, to prevent login token snooping.
 pub mod blowfish;
 
-mod blowfish_constants;
-
 /// Reading Excel header files (EXH).
 pub mod exh;