cl-typeck: More type inference

- Renamed "intrinsic" -> "primitive"
  - I thought it was funny, but it's just annoying.
- Rename "Uninferred" -> "Inferred"
  - It's a concrete type, but an inferred one.
- Add lifetimes to the Entry API
- Categorize does not care about recursive types. You can't have a recursive AST.
- Added helpful constructors to the inference engine
- Added some overloadable operators to the inference engine
  - These are a MAJOR work in progress
- Reorganized the Inference implementation file by functionality.

stdlib:
- Updated standard library.

stdlib/std.cl

@@ -1,7 +1,11 @@
 //! # The Conlang Standard Library
 
 pub mod preamble {
-    pub use super::{num::*, str::str};
+    pub use super::{
+        num::*,
+        range::{RangeExc, RangeInc},
+        str::str,
+    };
 }
 
 pub mod num;