Transition to new literals compiling.

Tests still need work, as does the implementation for json.

src/renderer/renderer.rs

@@ -477,9 +477,8 @@ impl<'a> DustRenderer<'a> {
         match param_map.get(key) {
             None => None,
             Some(rval) => match rval {
-                RValue::RVString(text) => Some(Ok(text)),
+                RValue::RVLiteral(literal) => Some(Ok(literal)),
                 RValue::RVPath(path) => Some(walk_path(breadcrumbs, &path.keys)),
-                RValue::RVPositiveInteger(num) => Some(Ok(num)),
             },
         }
     }