Undo the getters change.

The getters were a good idea, but if we are going to support editing later, we will need to expose the fields or write A LOT of boiler-plate. The getters also would prevent people from moving values out of the AST without even more boiler-plate. It is simply not worth it at this stage, so we will need to tolerate frequently changing semver versions as the public interface changes since *every* field in the AST is public.

src/compare/diff.rs

@@ -439,10 +439,13 @@ pub fn compare_document<'s>(
     }
 
     // TODO: Compare :path
+    // :path is a quoted string to the absolute path of the document.
+    let document_path = get_property_quoted_string(emacs, ":path")?;
 
     // Compare category
+    // :CATEGORY is specified either from "#+CATEGORY:" or it is the file name without the ".org" extension.
     let category = get_property_quoted_string(emacs, ":CATEGORY")?;
-    match (category.as_ref(), rust.category) {
+    match (category.as_ref(), rust.category.as_ref()) {
         (None, None) => {}
         (None, Some(_)) | (Some(_), None) => {
             this_status = DiffStatus::Bad;