Moved fields into separate module.

src/lib.rs

@@ -1,16 +1,16 @@
 mod data_director;
+mod field;
 mod message;
 mod mtterror;
 mod name;
 mod router;
 
 use data_director::{Include, Path, RegMsg, Register};
+use field::{Field, FieldType};
 use message::{
-    Action, Addition, CalcValue, Calculation, Clock, CreateDoc, Field, FieldType, Message, Operand,
-    Session,
+    Action, Addition, CalcValue, Calculation, Clock, CreateDoc, Message, Operand, Session,
 };
 pub use message::{MsgAction, Query};
-use mtterror::MTTError;
 use name::{Name, NameType};
 use router::Queue;
 use std::sync::mpsc::{channel, Receiver};