in progress commit

- fixed errors in func and vars blocking testing
- use box references in call and eval
Still need to fix the tests themselves....

src/eval.rs

@@ -25,9 +25,9 @@ use crate::vars::VTable;
  * representing the simplest possible form of the input
  */
 pub fn eval(
-    _ast: Box<Cell>,
-    _vars: Box<VTable>,
-    _funcs: Box<FTable>,
+    _ast: &Box<Cell>,
+    _vars: &Box<VTable>,
+    _funcs: &Box<FTable>,
     _sym_loose: bool
 ) -> Result<Box<Cell>, String> {
     Err("Unimplemented".to_string())