refactor: major overhaul

* Refactor: Remove all `Ref` wrapper types.
* Refactor: Make `SubjectNode` and `ObjectNode` into concrete enums.
* Refactor: Remove `Equiv` trait and rely on `PartialEq` instead.
* Refactor: Create new `Implementation` trait and
  `simple::Implementation` to hold the set of factories.

rdftk_core/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "rdftk_core"
-version = "0.4.4"
+version = "0.4.5"
 authors = ["Simon Johnston <[email protected]>"]
 edition = "2021"
 description = "This crate provides the core RDF data model; concrete implementations for Statements and Literals, along with a Resource type that provides a builder-like experience for models."

rdftk_core/README.md

@@ -52,6 +52,14 @@ pub fn make_statements() -> StatementList {
 
 ## Changes
 
+### Version 0.4.5
+
+* Refactor: Remove all `Ref` wrapper types.
+* Refactor: Make `SubjectNode` and `ObjectNode` into concrete enums.
+* Refactor: Remove `Equiv` trait and rely on `PartialEq` instead.
+* Refactor: Create new `Implementation` trait and `simple::Implementation` to hold
+  the set of factories.
+
 ### Version 0.4.4
 
 * Refactor: re-wrote `Error` type and removed `error_chain` dependency.