Use once_cell to allow for global static immutable options

So they don't have to be passed around all over the place

src/server.rs

@@ -3,19 +3,18 @@ use std::io::{BufRead, BufReader, Error, ErrorKind, Read, Write};
 use std::net::Shutdown;
 use std::os::unix::net::UnixStream;
 
-use crate::options::Opt;
+use crate::options::OPTIONS;
 
 const RESPONSE_NO: [u8; 4] = [0x0, 0x2, b'N', b'O'];
 const RESPONSE_OK: [u8; 4] = [0x0, 0x2, b'O', b'K'];
 
 pub struct Server {
-    options: Opt,
     stream: UnixStream,
 }
 
 impl Server {
-    pub fn new(options: Opt, stream: UnixStream) -> Result<Server, Error> {
-        Ok(Server { options, stream })
+    pub fn new(stream: UnixStream) -> Result<Server, Error> {
+        Ok(Server { stream })
     }
 
     /// The saslauthd protocol transmits strings as
@@ -60,7 +59,7 @@ impl Server {
             return Ok(false);
         }
 
-        let mut password_file = self.options.passwords.clone();
+        let mut password_file = OPTIONS.passwords.clone();
         password_file.push(&userid);
 
         let file = File::open(password_file)?;